From f3bf8d3110b852b8f338898c3237d16a74360cf3 Mon Sep 17 00:00:00 2001
From: Jay Berkenbilt
-The HTML documentation for PCRE comprises the following pages:
-
-There are also individual pages that summarize the interface for each function
-in the library:
-
-The PCRE library is a set of functions that implement regular expression
-pattern matching using the same syntax and semantics as Perl, with just a few
-differences. The current implementation of PCRE (release 4.x) corresponds
-approximately with Perl 5.8, including support for UTF-8 encoded strings.
-However, this support has to be explicitly enabled; it is not the default.
-
-PCRE is written in C and released as a C library. However, a number of people
-have written wrappers and interfaces of various kinds. A C++ class is included
-in these contributions, which can be found in the Contrib directory at
-the primary FTP site, which is:
-
-Details of exactly which Perl regular expression features are and are not
-supported by PCRE are given in separate documents. See the
-pcrepattern
-and
-pcrecompat
-pages.
-
-Some features of PCRE can be included, excluded, or changed when the library is
-built. The
-pcre_config()
-function makes it possible for a client to discover which features are
-available. Documentation about building PCRE for various operating systems can
-be found in the README file in the source distribution.
-
-The user documentation for PCRE has been split up into a number of different
-sections. In the "man" format, each of these is a separate "man page". In the
-HTML format, each is a separate page, linked from the index page. In the plain
-text format, all the sections are concatenated, for ease of searching. The
-sections are as follows:
-
-Perl-compatible Regular Expressions (PCRE)
-
-
-
-
-
-pcre
- Introductory page
-
-pcreapi
- PCRE's native API
-
-pcrebuild
- Options for building PCRE
-
-pcrecallout
- The callout facility
-
-pcrecompat
- Compability with Perl
-
-pcregrep
- The pcregrep command
-
-pcrepattern
- Regular expressions supported by PCRE
-
-pcreperform
- Some comments on performance
-
-pcreposix
- The POSIX API to the PCRE library
-
-pcresample
- Description of the sample program
-pcretest
- The pcretest command for testing PCRE
-
-
-
-
diff --git a/external-libs/pcre/doc/html/pcre.html b/external-libs/pcre/doc/html/pcre.html
deleted file mode 100644
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--- a/external-libs/pcre/doc/html/pcre.html
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@@ -1,190 +0,0 @@
-
-
-
-
-pcre_compile
- Compile a regular expression
-
-pcre_config
- Show build-time configuration options
-
-pcre_copy_named_substring
- Extract named substring into given buffer
-
-pcre_copy_substring
- Extract numbered substring into given buffer
-
-pcre_exec
- Match a compiled pattern to a subject string
-
-pcre_free_substring
- Free extracted substring
-
-pcre_free_substring_list
- Free list of extracted substrings
-
-pcre_fullinfo
- Extract information about a pattern
-
-pcre_get_named_substring
- Extract named substring into new memory
-
-pcre_get_stringnumber
- Convert captured string name to number
-
-pcre_get_substring
- Extract numbered substring into new memory
-
-pcre_get_substring_list
- Extract all substrings into new memory
-
-pcre_info
- Obsolete information extraction function
-
-pcre_maketables
- Build character tables in current locale
-
-pcre_study
- Study a compiled pattern
-pcre_version
- Return PCRE version and release date
-
-
DESCRIPTION
-
USER DOCUMENTATION
-
- pcre this document
- pcreapi details of PCRE's native API
- pcrebuild options for building PCRE
- pcrecallout details of the callout feature
- pcrecompat discussion of Perl compatibility
- pcregrep description of the pcregrep command
- pcrepattern syntax and semantics of supported
- regular expressions
- pcreperform discussion of performance issues
- pcreposix the POSIX-compatible API
- pcresample discussion of the sample program
- pcretest the pcretest testing command
-
-
-In addition, in the "man" and HTML formats, there is a short page for each -library function, listing its arguments and results. -
--There are some size limitations in PCRE but it is hoped that they will never in -practice be relevant. -
--The maximum length of a compiled pattern is 65539 (sic) bytes if PCRE is -compiled with the default internal linkage size of 2. If you want to process -regular expressions that are truly enormous, you can compile PCRE with an -internal linkage size of 3 or 4 (see the README file in the source -distribution and the -pcrebuild -documentation for details). If these cases the limit is substantially larger. -However, the speed of execution will be slower. -
--All values in repeating quantifiers must be less than 65536. -The maximum number of capturing subpatterns is 65535. -
--There is no limit to the number of non-capturing subpatterns, but the maximum -depth of nesting of all kinds of parenthesized subpattern, including capturing -subpatterns, assertions, and other types of subpattern, is 200. -
--The maximum length of a subject string is the largest positive number that an -integer variable can hold. However, PCRE uses recursion to handle subpatterns -and indefinite repetition. This means that the available stack space may limit -the size of a subject string that can be processed by certain patterns. -
--Starting at release 3.3, PCRE has had some support for character strings -encoded in the UTF-8 format. For release 4.0 this has been greatly extended to -cover most common requirements. -
--In order process UTF-8 strings, you must build PCRE to include UTF-8 support in -the code, and, in addition, you must call -pcre_compile() -with the PCRE_UTF8 option flag. When you do this, both the pattern and any -subject strings that are matched against it are treated as UTF-8 strings -instead of just strings of bytes. -
--If you compile PCRE with UTF-8 support, but do not use it at run time, the -library will be a bit bigger, but the additional run time overhead is limited -to testing the PCRE_UTF8 flag in several places, so should not be very large. -
--The following comments apply when PCRE is running in UTF-8 mode: -
--1. When you set the PCRE_UTF8 flag, the strings passed as patterns and subjects -are checked for validity on entry to the relevant functions. If an invalid -UTF-8 string is passed, an error return is given. In some situations, you may -already know that your strings are valid, and therefore want to skip these -checks in order to improve performance. If you set the PCRE_NO_UTF8_CHECK flag -at compile time or at run time, PCRE assumes that the pattern or subject it -is given (respectively) contains only valid UTF-8 codes. In this case, it does -not diagnose an invalid UTF-8 string. If you pass an invalid UTF-8 string to -PCRE when PCRE_NO_UTF8_CHECK is set, the results are undefined. Your program -may crash. -
--2. In a pattern, the escape sequence \x{...}, where the contents of the braces -is a string of hexadecimal digits, is interpreted as a UTF-8 character whose -code number is the given hexadecimal number, for example: \x{1234}. If a -non-hexadecimal digit appears between the braces, the item is not recognized. -This escape sequence can be used either as a literal, or within a character -class. -
--3. The original hexadecimal escape sequence, \xhh, matches a two-byte UTF-8 -character if the value is greater than 127. -
--4. Repeat quantifiers apply to complete UTF-8 characters, not to individual -bytes, for example: \x{100}{3}. -
--5. The dot metacharacter matches one UTF-8 character instead of a single byte. -
--6. The escape sequence \C can be used to match a single byte in UTF-8 mode, -but its use can lead to some strange effects. -
--7. The character escapes \b, \B, \d, \D, \s, \S, \w, and \W correctly -test characters of any code value, but the characters that PCRE recognizes as -digits, spaces, or word characters remain the same set as before, all with -values less than 256. -
--8. Case-insensitive matching applies only to characters whose values are less -than 256. PCRE does not support the notion of "case" for higher-valued -characters. -
--9. PCRE does not support the use of Unicode tables and properties or the Perl -escapes \p, \P, and \X. -
-
-Philip Hazel <ph10@cam.ac.uk>
-
-University Computing Service,
-
-Cambridge CB2 3QG, England.
-
-Phone: +44 1223 334714
-
-Last updated: 20 August 2003
-
-Copyright © 1997-2003 University of Cambridge.
diff --git a/external-libs/pcre/doc/html/pcre_compile.html b/external-libs/pcre/doc/html/pcre_compile.html
deleted file mode 100644
index e1a43793..00000000
--- a/external-libs/pcre/doc/html/pcre_compile.html
+++ /dev/null
@@ -1,71 +0,0 @@
-
-
-#include <pcre.h> -
--pcre *pcre_compile(const char *pattern, int options, -const char **errptr, int *erroffset, -const unsigned char *tableptr); -
--This function compiles a regular expression into an internal form. Its -arguments are: -
--
- pattern A zero-terminated string containing the - regular expression to be compiled - options Zero or more option bits - errptr Where to put an error message - erroffset Offset in pattern where error was found - tableptr Pointer to character tables, or NULL to - use the built-in default -- -
-The option bits are: -
--
- PCRE_ANCHORED Force pattern anchoring - PCRE_CASELESS Do caseless matching - PCRE_DOLLAR_ENDONLY $ not to match newline at end - PCRE_DOTALL . matches anything including NL - PCRE_EXTENDED Ignore whitespace and # comments - PCRE_EXTRA PCRE extra features - (not much use currently) - PCRE_MULTILINE ^ and $ match newlines within data - PCRE_NO_AUTO_CAPTURE Disable numbered capturing paren- - theses (named ones available) - PCRE_UNGREEDY Invert greediness of quantifiers - PCRE_UTF8 Run in UTF-8 mode - PCRE_NO_UTF8_CHECK Do not check the pattern for UTF-8 - validity (only relevant if - PCRE_UTF8 is set) -- -
-PCRE must be compiled with UTF-8 support in order to use PCRE_UTF8 -(or PCRE_NO_UTF8_CHECK). -
--The yield of the function is a pointer to a private data structure that -contains the compiled pattern, or NULL if an error was detected. -
--There is a complete description of the PCRE API in the -pcreapi -page. diff --git a/external-libs/pcre/doc/html/pcre_config.html b/external-libs/pcre/doc/html/pcre_config.html deleted file mode 100644 index 3328b792..00000000 --- a/external-libs/pcre/doc/html/pcre_config.html +++ /dev/null @@ -1,56 +0,0 @@ - -
--#include <pcre.h> -
--int pcre_config(int what, void *where); -
--This function makes it possible for a client program to find out which optional -features are available in the version of the PCRE library it is using. Its -arguments are as follows: -
--
- what A code specifying what information is required - where Points to where to put the data -- -
-The available codes are: -
--
- PCRE_CONFIG_LINK_SIZE Internal link size: 2, 3, or 4 - PCRE_CONFIG_MATCH_LIMIT Internal resource limit - PCRE_CONFIG_NEWLINE Value of the newline character - PCRE_CONFIG_POSIX_MALLOC_THRESHOLD - Threshold of return slots, above - which malloc() is used by - the POSIX API - PCRE_CONFIG_STACKRECURSE Recursion implementation (1=stack 0=heap) - PCRE_CONFIG_UTF8 Availability of UTF-8 support (1=yes 0=no) -- -
-The function yields 0 on success or PCRE_ERROR_BADOPTION otherwise. -
--There is a complete description of the PCRE native API in the -pcreapi -page, and a description of the POSIX API in the -pcreposix -page. diff --git a/external-libs/pcre/doc/html/pcre_copy_named_substring.html b/external-libs/pcre/doc/html/pcre_copy_named_substring.html deleted file mode 100644 index 3b1da364..00000000 --- a/external-libs/pcre/doc/html/pcre_copy_named_substring.html +++ /dev/null @@ -1,46 +0,0 @@ - -
--#include <pcre.h> -
--int pcre_copy_named_substring(const pcre *code, -const char *subject, int *ovector, -int stringcount, const char *stringname, -char *buffer, int buffersize); -
--This is a convenience function for extracting a captured substring, identified -by name, into a given buffer. The arguments are: -
--
- code Pattern that was successfully matched - subject Subject that has been successfully matched - ovector Offset vector that pcre_exec() used - stringcount Value returned by pcre_exec() - stringname Name of the required substring - buffer Buffer to receive the string - buffersize Size of buffer -- -
-The yield is the length of the substring, PCRE_ERROR_NOMEMORY if the buffer was -too small, or PCRE_ERROR_NOSUBSTRING if the string name is invalid. -
--There is a complete description of the PCRE API in the -pcreapi -page. diff --git a/external-libs/pcre/doc/html/pcre_copy_substring.html b/external-libs/pcre/doc/html/pcre_copy_substring.html deleted file mode 100644 index f5b9b553..00000000 --- a/external-libs/pcre/doc/html/pcre_copy_substring.html +++ /dev/null @@ -1,44 +0,0 @@ - -
--#include <pcre.h> -
--int pcre_copy_substring(const char *subject, int *ovector, -int stringcount, int stringnumber, char *buffer, -int buffersize); -
--This is a convenience function for extracting a captured substring into a given -buffer. The arguments are: -
--
- subject Subject that has been successfully matched - ovector Offset vector that pcre_exec() used - stringcount Value returned by pcre_exec() - stringnumber Number of the required substring - buffer Buffer to receive the string - buffersize Size of buffer -- -
-The yield is the legnth of the string, PCRE_ERROR_NOMEMORY if the buffer was -too small, or PCRE_ERROR_NOSUBSTRING if the string number is invalid. -
--There is a complete description of the PCRE API in the -pcreapi -page. diff --git a/external-libs/pcre/doc/html/pcre_exec.html b/external-libs/pcre/doc/html/pcre_exec.html deleted file mode 100644 index cf86dfda..00000000 --- a/external-libs/pcre/doc/html/pcre_exec.html +++ /dev/null @@ -1,58 +0,0 @@ - -
--#include <pcre.h> -
--int pcre_exec(const pcre *code, const pcre_extra *extra, -const char *subject, int length, int startoffset, -int options, int *ovector, int ovecsize); -
--This function matches a compiled regular expression against a given subject -string, and returns offsets to capturing subexpressions. Its arguments are: -
--
- code Points to the compiled pattern - extra Points to an associated pcre_extra structure, - or is NULL - subject Points to the subject string - length Length of the subject string, in bytes - startoffset Offset in bytes in the subject at which to - start matching - options Option bits - ovector Points to a vector of ints for result offsets - ovecsize Size of the vector (a multiple of 3) -- -
-The options are: -
--
- PCRE_ANCHORED Match only at the first position - PCRE_NOTBOL Subject is not the beginning of a line - PCRE_NOTEOL Subject is not the end of a line - PCRE_NOTEMPTY An empty string is not a valid match - PCRE_NO_UTF8_CHECK Do not check the subject for UTF-8 - validity (only relevant if PCRE_UTF8 - was set at compile time) -- -
-There is a complete description of the PCRE API in the -pcreapi -page. diff --git a/external-libs/pcre/doc/html/pcre_free_substring.html b/external-libs/pcre/doc/html/pcre_free_substring.html deleted file mode 100644 index 08b16078..00000000 --- a/external-libs/pcre/doc/html/pcre_free_substring.html +++ /dev/null @@ -1,29 +0,0 @@ - -
--#include <pcre.h> -
--void pcre_free_substring(const char *stringptr); -
--This is a convenience function for freeing the store obtained by a previous -call to pcre_get_substring() or pcre_get_named_substring(). Its -only argument is a pointer to the string. -
--There is a complete description of the PCRE API in the -pcreapi -page. diff --git a/external-libs/pcre/doc/html/pcre_free_substring_list.html b/external-libs/pcre/doc/html/pcre_free_substring_list.html deleted file mode 100644 index c130f281..00000000 --- a/external-libs/pcre/doc/html/pcre_free_substring_list.html +++ /dev/null @@ -1,29 +0,0 @@ - -
--#include <pcre.h> -
--void pcre_free_substring_list(const char **stringptr); -
--This is a convenience function for freeing the store obtained by a previous -call to pcre_get_substring_list(). Its only argument is a pointer to the -list of string pointers. -
--There is a complete description of the PCRE API in the -pcreapi -page. diff --git a/external-libs/pcre/doc/html/pcre_fullinfo.html b/external-libs/pcre/doc/html/pcre_fullinfo.html deleted file mode 100644 index f43fa65f..00000000 --- a/external-libs/pcre/doc/html/pcre_fullinfo.html +++ /dev/null @@ -1,68 +0,0 @@ - -
--#include <pcre.h> -
--int pcre_fullinfo(const pcre *code, const pcre_extra *extra, -int what, void *where); -
--This function returns information about a compiled pattern. Its arguments are: -
--
- code Compiled regular expression - extra Result of pcre_study() or NULL - what What information is required - where Where to put the information -- -
-The following information is available: -
--
- PCRE_INFO_BACKREFMAX Number of highest back reference - PCRE_INFO_CAPTURECOUNT Number of capturing subpatterns - PCRE_INFO_FIRSTBYTE Fixed first byte for a match, or - -1 for start of string - or after newline, or - -2 otherwise - PCRE_INFO_FIRSTTABLE Table of first bytes - (after studying) - PCRE_INFO_LASTLITERAL Literal last byte required - PCRE_INFO_NAMECOUNT Number of named subpatterns - PCRE_INFO_NAMEENTRYSIZE Size of name table entry - PCRE_INFO_NAMETABLE Pointer to name table - PCRE_INFO_OPTIONS Options used for compilation - PCRE_INFO_SIZE Size of compiled pattern -- -
-The yield of the function is zero on success or: -
--
- PCRE_ERROR_NULL the argument code was NULL - the argument where was NULL - PCRE_ERROR_BADMAGIC the "magic number" was not found - PCRE_ERROR_BADOPTION the value of what was invalid -- -
-There is a complete description of the PCRE API in the -pcreapi -page. diff --git a/external-libs/pcre/doc/html/pcre_get_named_substring.html b/external-libs/pcre/doc/html/pcre_get_named_substring.html deleted file mode 100644 index 89a2beeb..00000000 --- a/external-libs/pcre/doc/html/pcre_get_named_substring.html +++ /dev/null @@ -1,46 +0,0 @@ - -
--#include <pcre.h> -
--int pcre_get_named_substring(const pcre *code, -const char *subject, int *ovector, -int stringcount, const char *stringname, -const char **stringptr); -
--This is a convenience function for extracting a captured substring by name. The -arguments are: -
--
- code Compiled pattern - subject Subject that has been successfully matched - ovector Offset vector that pcre_exec() used - stringcount Value returned by pcre_exec() - stringname Name of the required substring - stringptr Where to put the string pointer -- -
-The yield is the length of the extracted substring, PCRE_ERROR_NOMEMORY if -sufficient memory could not be obtained, or PCRE_ERROR_NOSUBSTRING if the -string name is invalid. -
--There is a complete description of the PCRE API in the -pcreapi -page. diff --git a/external-libs/pcre/doc/html/pcre_get_stringnumber.html b/external-libs/pcre/doc/html/pcre_get_stringnumber.html deleted file mode 100644 index ee1c0a9c..00000000 --- a/external-libs/pcre/doc/html/pcre_get_stringnumber.html +++ /dev/null @@ -1,39 +0,0 @@ - -
--#include <pcre.h> -
--int pcre_get_stringnumber(const pcre *code, -const char *name); -
--This convenience function finds the number of a named substring capturing -parenthesis in a compiled pattern. Its arguments are: -
--
- code Compiled regular expression - name Name whose number is required -- -
-The yield of the function is the number of the parenthesis if the name is -found, or PCRE_ERROR_NOSUBSTRING otherwise. -
--There is a complete description of the PCRE API in the -pcreapi -page. diff --git a/external-libs/pcre/doc/html/pcre_get_substring.html b/external-libs/pcre/doc/html/pcre_get_substring.html deleted file mode 100644 index 2a55c10f..00000000 --- a/external-libs/pcre/doc/html/pcre_get_substring.html +++ /dev/null @@ -1,44 +0,0 @@ - -
--#include <pcre.h> -
--int pcre_get_substring(const char *subject, int *ovector, -int stringcount, int stringnumber, -const char **stringptr); -
--This is a convenience function for extracting a captured substring. The -arguments are: -
--
- subject Subject that has been successfully matched - ovector Offset vector that pcre_exec() used - stringcount Value returned by pcre_exec() - stringnumber Number of the required substring - stringptr Where to put the string pointer -- -
-The yield is the length of the substring, PCRE_ERROR_NOMEMORY if sufficient -memory could not be obtained, or PCRE_ERROR_NOSUBSTRING if the string number is -invalid. -
--There is a complete description of the PCRE API in the -pcreapi -page. diff --git a/external-libs/pcre/doc/html/pcre_get_substring_list.html b/external-libs/pcre/doc/html/pcre_get_substring_list.html deleted file mode 100644 index 7e91f56b..00000000 --- a/external-libs/pcre/doc/html/pcre_get_substring_list.html +++ /dev/null @@ -1,41 +0,0 @@ - -
--#include <pcre.h> -
--int pcre_get_substring_list(const char *subject, -int *ovector, int stringcount, const char ***listptr); -
--This is a convenience function for extracting a list of all the captured -substrings. The arguments are: -
--
- subject Subject that has been successfully matched - ovector Offset vector that pcre_exec used - stringcount Value returned by pcre_exec - listptr Where to put a pointer to the list -- -
-The yield is zero on success or PCRE_ERROR_NOMEMORY if sufficient memory could -not be obtained. -
--There is a complete description of the PCRE API in the -pcreapi -page. diff --git a/external-libs/pcre/doc/html/pcre_info.html b/external-libs/pcre/doc/html/pcre_info.html deleted file mode 100644 index 97fc59b4..00000000 --- a/external-libs/pcre/doc/html/pcre_info.html +++ /dev/null @@ -1,28 +0,0 @@ - -
--#include <pcre.h> -
--int pcre_info(const pcre *code, int *optptr, int -*firstcharptr); -
--This function is obsolete. You should be using pcre_fullinfo() instead. -
--There is a complete description of the PCRE API in the -pcreapi -page. diff --git a/external-libs/pcre/doc/html/pcre_maketables.html b/external-libs/pcre/doc/html/pcre_maketables.html deleted file mode 100644 index ba3e026b..00000000 --- a/external-libs/pcre/doc/html/pcre_maketables.html +++ /dev/null @@ -1,31 +0,0 @@ - -
--#include <pcre.h> -
--const unsigned char *pcre_maketables(void); -
--This function builds a set of character tables which can be passed to -pcre_compile() to override PCRE's internal, built-in tables (which were -made by pcre_maketables() when PCRE was compiled). You might want to do -this if you are using a non-standard locale. The function yields a pointer to -the tables. -
--There is a complete description of the PCRE API in the -pcreapi -page. diff --git a/external-libs/pcre/doc/html/pcre_study.html b/external-libs/pcre/doc/html/pcre_study.html deleted file mode 100644 index f3727d1f..00000000 --- a/external-libs/pcre/doc/html/pcre_study.html +++ /dev/null @@ -1,45 +0,0 @@ - -
--#include <pcre.h> -
--pcre_extra *pcre_study(const pcre *code, int options, -const char **errptr); -
--This function studies a compiled pattern, to see if additional information can -be extracted that might speed up matching. Its arguments are: -
--
- code A compiled regular expression - options Options for pcre_study() - errptr Where to put an error message -- -
-If the function returns NULL, either it could not find any additional -information, or there was an error. You can tell the difference by looking at -the error value. It is NULL in first case. -
--There are currently no options defined; the value of the second argument should -always be zero. -
--There is a complete description of the PCRE API in the -pcreapi -page. diff --git a/external-libs/pcre/doc/html/pcre_version.html b/external-libs/pcre/doc/html/pcre_version.html deleted file mode 100644 index 35c47cd6..00000000 --- a/external-libs/pcre/doc/html/pcre_version.html +++ /dev/null @@ -1,28 +0,0 @@ - -
--#include <pcre.h> -
--char *pcre_version(void); -
--This function returns a character string that gives the version number of the -PCRE library, and its date of release. -
--There is a complete description of the PCRE API in the -pcreapi -page. diff --git a/external-libs/pcre/doc/html/pcreapi.html b/external-libs/pcre/doc/html/pcreapi.html deleted file mode 100644 index 8ae6fb1e..00000000 --- a/external-libs/pcre/doc/html/pcreapi.html +++ /dev/null @@ -1,1346 +0,0 @@ - -
--#include <pcre.h> -
--pcre *pcre_compile(const char *pattern, int options, -const char **errptr, int *erroffset, -const unsigned char *tableptr); -
--pcre_extra *pcre_study(const pcre *code, int options, -const char **errptr); -
--int pcre_exec(const pcre *code, const pcre_extra *extra, -const char *subject, int length, int startoffset, -int options, int *ovector, int ovecsize); -
--int pcre_copy_named_substring(const pcre *code, -const char *subject, int *ovector, -int stringcount, const char *stringname, -char *buffer, int buffersize); -
--int pcre_copy_substring(const char *subject, int *ovector, -int stringcount, int stringnumber, char *buffer, -int buffersize); -
--int pcre_get_named_substring(const pcre *code, -const char *subject, int *ovector, -int stringcount, const char *stringname, -const char **stringptr); -
--int pcre_get_stringnumber(const pcre *code, -const char *name); -
--int pcre_get_substring(const char *subject, int *ovector, -int stringcount, int stringnumber, -const char **stringptr); -
--int pcre_get_substring_list(const char *subject, -int *ovector, int stringcount, const char ***listptr); -
--void pcre_free_substring(const char *stringptr); -
--void pcre_free_substring_list(const char **stringptr); -
--const unsigned char *pcre_maketables(void); -
--int pcre_fullinfo(const pcre *code, const pcre_extra *extra, -int what, void *where); -
--int pcre_info(const pcre *code, int *optptr, int -*firstcharptr); -
--int pcre_config(int what, void *where); -
--char *pcre_version(void); -
--void *(*pcre_malloc)(size_t); -
--void (*pcre_free)(void *); -
--void *(*pcre_stack_malloc)(size_t); -
--void (*pcre_stack_free)(void *); -
--int (*pcre_callout)(pcre_callout_block *); -
--PCRE has its own native API, which is described in this document. There is also -a set of wrapper functions that correspond to the POSIX regular expression API. -These are described in the pcreposix documentation. -
--The native API function prototypes are defined in the header file pcre.h, -and on Unix systems the library itself is called libpcre.a, so can be -accessed by adding -lpcre to the command for linking an application which -calls it. The header file defines the macros PCRE_MAJOR and PCRE_MINOR to -contain the major and minor release numbers for the library. Applications can -use these to include support for different releases. -
--The functions pcre_compile(), pcre_study(), and pcre_exec() -are used for compiling and matching regular expressions. A sample program that -demonstrates the simplest way of using them is given in the file -pcredemo.c. The pcresample documentation describes how to run it. -
--There are convenience functions for extracting captured substrings from a -matched subject string. They are: -
--
- pcre_copy_substring() - pcre_copy_named_substring() - pcre_get_substring() - pcre_get_named_substring() - pcre_get_substring_list() -- -
-pcre_free_substring() and pcre_free_substring_list() are also -provided, to free the memory used for extracted strings. -
--The function pcre_maketables() is used (optionally) to build a set of -character tables in the current locale for passing to pcre_compile(). -
--The function pcre_fullinfo() is used to find out information about a -compiled pattern; pcre_info() is an obsolete version which returns only -some of the available information, but is retained for backwards compatibility. -The function pcre_version() returns a pointer to a string containing the -version of PCRE and its date of release. -
--The global variables pcre_malloc and pcre_free initially contain -the entry points of the standard malloc() and free() functions -respectively. PCRE calls the memory management functions via these variables, -so a calling program can replace them if it wishes to intercept the calls. This -should be done before calling any PCRE functions. -
--The global variables pcre_stack_malloc and pcre_stack_free are also -indirections to memory management functions. These special functions are used -only when PCRE is compiled to use the heap for remembering data, instead of -recursive function calls. This is a non-standard way of building PCRE, for use -in environments that have limited stacks. Because of the greater use of memory -management, it runs more slowly. Separate functions are provided so that -special-purpose external code can be used for this case. When used, these -functions are always called in a stack-like manner (last obtained, first -freed), and always for memory blocks of the same size. -
--The global variable pcre_callout initially contains NULL. It can be set -by the caller to a "callout" function, which PCRE will then call at specified -points during a matching operation. Details are given in the pcrecallout -documentation. -
--The PCRE functions can be used in multi-threading applications, with the -proviso that the memory management functions pointed to by pcre_malloc, -pcre_free, pcre_stack_malloc, and pcre_stack_free, and the -callout function pointed to by pcre_callout, are shared by all threads. -
--The compiled form of a regular expression is not altered during matching, so -the same compiled pattern can safely be used by several threads at once. -
--int pcre_config(int what, void *where); -
--The function pcre_config() makes it possible for a PCRE client to -discover which optional features have been compiled into the PCRE library. The -pcrebuild -documentation has more details about these optional features. -
--The first argument for pcre_config() is an integer, specifying which -information is required; the second argument is a pointer to a variable into -which the information is placed. The following information is available: -
--
- PCRE_CONFIG_UTF8 -- -
-The output is an integer that is set to one if UTF-8 support is available; -otherwise it is set to zero. -
--
- PCRE_CONFIG_NEWLINE -- -
-The output is an integer that is set to the value of the code that is used for -the newline character. It is either linefeed (10) or carriage return (13), and -should normally be the standard character for your operating system. -
--
- PCRE_CONFIG_LINK_SIZE -- -
-The output is an integer that contains the number of bytes used for internal -linkage in compiled regular expressions. The value is 2, 3, or 4. Larger values -allow larger regular expressions to be compiled, at the expense of slower -matching. The default value of 2 is sufficient for all but the most massive -patterns, since it allows the compiled pattern to be up to 64K in size. -
--
- PCRE_CONFIG_POSIX_MALLOC_THRESHOLD -- -
-The output is an integer that contains the threshold above which the POSIX -interface uses malloc() for output vectors. Further details are given in -the pcreposix documentation. -
--
- PCRE_CONFIG_MATCH_LIMIT -- -
-The output is an integer that gives the default limit for the number of -internal matching function calls in a pcre_exec() execution. Further -details are given with pcre_exec() below. -
--
- PCRE_CONFIG_STACKRECURSE -- -
-The output is an integer that is set to one if internal recursion is -implemented by recursive function calls that use the stack to remember their -state. This is the usual way that PCRE is compiled. The output is zero if PCRE -was compiled to use blocks of data on the heap instead of recursive function -calls. In this case, pcre_stack_malloc and pcre_stack_free are -called to manage memory blocks on the heap, thus avoiding the use of the stack. -
--pcre *pcre_compile(const char *pattern, int options, -const char **errptr, int *erroffset, -const unsigned char *tableptr); -
--The function pcre_compile() is called to compile a pattern into an -internal form. The pattern is a C string terminated by a binary zero, and -is passed in the argument pattern. A pointer to a single block of memory -that is obtained via pcre_malloc is returned. This contains the compiled -code and related data. The pcre type is defined for the returned block; -this is a typedef for a structure whose contents are not externally defined. It -is up to the caller to free the memory when it is no longer required. -
--Although the compiled code of a PCRE regex is relocatable, that is, it does not -depend on memory location, the complete pcre data block is not -fully relocatable, because it contains a copy of the tableptr argument, -which is an address (see below). -
--The options argument contains independent bits that affect the -compilation. It should be zero if no options are required. Some of the options, -in particular, those that are compatible with Perl, can also be set and unset -from within the pattern (see the detailed description of regular expressions -in the pcrepattern documentation). For these options, the contents of the -options argument specifies their initial settings at the start of -compilation and execution. The PCRE_ANCHORED option can be set at the time of -matching as well as at compile time. -
--If errptr is NULL, pcre_compile() returns NULL immediately. -Otherwise, if compilation of a pattern fails, pcre_compile() returns -NULL, and sets the variable pointed to by errptr to point to a textual -error message. The offset from the start of the pattern to the character where -the error was discovered is placed in the variable pointed to by -erroffset, which must not be NULL. If it is, an immediate error is given. -
--If the final argument, tableptr, is NULL, PCRE uses a default set of -character tables which are built when it is compiled, using the default C -locale. Otherwise, tableptr must be the result of a call to -pcre_maketables(). See the section on locale support below. -
--This code fragment shows a typical straightforward call to pcre_compile(): -
--
- pcre *re; - const char *error; - int erroffset; - re = pcre_compile( - "^A.*Z", /* the pattern */ - 0, /* default options */ - &error, /* for error message */ - &erroffset, /* for error offset */ - NULL); /* use default character tables */ -- -
-The following option bits are defined: -
--
- PCRE_ANCHORED -- -
-If this bit is set, the pattern is forced to be "anchored", that is, it is -constrained to match only at the first matching point in the string which is -being searched (the "subject string"). This effect can also be achieved by -appropriate constructs in the pattern itself, which is the only way to do it in -Perl. -
--
- PCRE_CASELESS -- -
-If this bit is set, letters in the pattern match both upper and lower case -letters. It is equivalent to Perl's /i option, and it can be changed within a -pattern by a (?i) option setting. -
--
- PCRE_DOLLAR_ENDONLY -- -
-If this bit is set, a dollar metacharacter in the pattern matches only at the -end of the subject string. Without this option, a dollar also matches -immediately before the final character if it is a newline (but not before any -other newlines). The PCRE_DOLLAR_ENDONLY option is ignored if PCRE_MULTILINE is -set. There is no equivalent to this option in Perl, and no way to set it within -a pattern. -
--
- PCRE_DOTALL -- -
-If this bit is set, a dot metacharater in the pattern matches all characters, -including newlines. Without it, newlines are excluded. This option is -equivalent to Perl's /s option, and it can be changed within a pattern by a -(?s) option setting. A negative class such as [^a] always matches a newline -character, independent of the setting of this option. -
--
- PCRE_EXTENDED -- -
-If this bit is set, whitespace data characters in the pattern are totally -ignored except when escaped or inside a character class. Whitespace does not -include the VT character (code 11). In addition, characters between an -unescaped # outside a character class and the next newline character, -inclusive, are also ignored. This is equivalent to Perl's /x option, and it can -be changed within a pattern by a (?x) option setting. -
--This option makes it possible to include comments inside complicated patterns. -Note, however, that this applies only to data characters. Whitespace characters -may never appear within special character sequences in a pattern, for example -within the sequence (?( which introduces a conditional subpattern. -
--
- PCRE_EXTRA -- -
-This option was invented in order to turn on additional functionality of PCRE -that is incompatible with Perl, but it is currently of very little use. When -set, any backslash in a pattern that is followed by a letter that has no -special meaning causes an error, thus reserving these combinations for future -expansion. By default, as in Perl, a backslash followed by a letter with no -special meaning is treated as a literal. There are at present no other features -controlled by this option. It can also be set by a (?X) option setting within a -pattern. -
--
- PCRE_MULTILINE -- -
-By default, PCRE treats the subject string as consisting of a single "line" of -characters (even if it actually contains several newlines). The "start of line" -metacharacter (^) matches only at the start of the string, while the "end of -line" metacharacter ($) matches only at the end of the string, or before a -terminating newline (unless PCRE_DOLLAR_ENDONLY is set). This is the same as -Perl. -
--When PCRE_MULTILINE it is set, the "start of line" and "end of line" constructs -match immediately following or immediately before any newline in the subject -string, respectively, as well as at the very start and end. This is equivalent -to Perl's /m option, and it can be changed within a pattern by a (?m) option -setting. If there are no "\n" characters in a subject string, or no -occurrences of ^ or $ in a pattern, setting PCRE_MULTILINE has no effect. -
--
- PCRE_NO_AUTO_CAPTURE -- -
-If this option is set, it disables the use of numbered capturing parentheses in -the pattern. Any opening parenthesis that is not followed by ? behaves as if it -were followed by ?: but named parentheses can still be used for capturing (and -they acquire numbers in the usual way). There is no equivalent of this option -in Perl. -
--
- PCRE_UNGREEDY -- -
-This option inverts the "greediness" of the quantifiers so that they are not -greedy by default, but become greedy if followed by "?". It is not compatible -with Perl. It can also be set by a (?U) option setting within the pattern. -
--
- PCRE_UTF8 -- -
-This option causes PCRE to regard both the pattern and the subject as strings -of UTF-8 characters instead of single-byte character strings. However, it is -available only if PCRE has been built to include UTF-8 support. If not, the use -of this option provokes an error. Details of how this option changes the -behaviour of PCRE are given in the -section on UTF-8 support -in the main -pcre -page. -
--
- PCRE_NO_UTF8_CHECK -- -
-When PCRE_UTF8 is set, the validity of the pattern as a UTF-8 string is -automatically checked. If an invalid UTF-8 sequence of bytes is found, -pcre_compile() returns an error. If you already know that your pattern is -valid, and you want to skip this check for performance reasons, you can set the -PCRE_NO_UTF8_CHECK option. When it is set, the effect of passing an invalid -UTF-8 string as a pattern is undefined. It may cause your program to crash. -Note that there is a similar option for suppressing the checking of subject -strings passed to pcre_exec(). -
--pcre_extra *pcre_study(const pcre *code, int options, -const char **errptr); -
--When a pattern is going to be used several times, it is worth spending more -time analyzing it in order to speed up the time taken for matching. The -function pcre_study() takes a pointer to a compiled pattern as its first -argument. If studing the pattern produces additional information that will help -speed up matching, pcre_study() returns a pointer to a pcre_extra -block, in which the study_data field points to the results of the study. -
--The returned value from a pcre_study() can be passed directly to -pcre_exec(). However, the pcre_extra block also contains other -fields that can be set by the caller before the block is passed; these are -described below. If studying the pattern does not produce any additional -information, pcre_study() returns NULL. In that circumstance, if the -calling program wants to pass some of the other fields to pcre_exec(), it -must set up its own pcre_extra block. -
--The second argument contains option bits. At present, no options are defined -for pcre_study(), and this argument should always be zero. -
--The third argument for pcre_study() is a pointer for an error message. If -studying succeeds (even if no data is returned), the variable it points to is -set to NULL. Otherwise it points to a textual error message. You should -therefore test the error pointer for NULL after calling pcre_study(), to -be sure that it has run successfully. -
--This is a typical call to pcre_study(): -
--
- pcre_extra *pe; - pe = pcre_study( - re, /* result of pcre_compile() */ - 0, /* no options exist */ - &error); /* set to NULL or points to a message */ -- -
-At present, studying a pattern is useful only for non-anchored patterns that do -not have a single fixed starting character. A bitmap of possible starting -characters is created. -
--PCRE handles caseless matching, and determines whether characters are letters, -digits, or whatever, by reference to a set of tables. When running in UTF-8 -mode, this applies only to characters with codes less than 256. The library -contains a default set of tables that is created in the default C locale when -PCRE is compiled. This is used when the final argument of pcre_compile() -is NULL, and is sufficient for many applications. -
--An alternative set of tables can, however, be supplied. Such tables are built -by calling the pcre_maketables() function, which has no arguments, in the -relevant locale. The result can then be passed to pcre_compile() as often -as necessary. For example, to build and use tables that are appropriate for the -French locale (where accented characters with codes greater than 128 are -treated as letters), the following code could be used: -
--
- setlocale(LC_CTYPE, "fr"); - tables = pcre_maketables(); - re = pcre_compile(..., tables); -- -
-The tables are built in memory that is obtained via pcre_malloc. The -pointer that is passed to pcre_compile is saved with the compiled -pattern, and the same tables are used via this pointer by pcre_study() -and pcre_exec(). Thus, for any single pattern, compilation, studying and -matching all happen in the same locale, but different patterns can be compiled -in different locales. It is the caller's responsibility to ensure that the -memory containing the tables remains available for as long as it is needed. -
--int pcre_fullinfo(const pcre *code, const pcre_extra *extra, -int what, void *where); -
--The pcre_fullinfo() function returns information about a compiled -pattern. It replaces the obsolete pcre_info() function, which is -nevertheless retained for backwards compability (and is documented below). -
--The first argument for pcre_fullinfo() is a pointer to the compiled -pattern. The second argument is the result of pcre_study(), or NULL if -the pattern was not studied. The third argument specifies which piece of -information is required, and the fourth argument is a pointer to a variable -to receive the data. The yield of the function is zero for success, or one of -the following negative numbers: -
--
- PCRE_ERROR_NULL the argument code was NULL - the argument where was NULL - PCRE_ERROR_BADMAGIC the "magic number" was not found - PCRE_ERROR_BADOPTION the value of what was invalid -- -
-Here is a typical call of pcre_fullinfo(), to obtain the length of the -compiled pattern: -
--
- int rc; - unsigned long int length; - rc = pcre_fullinfo( - re, /* result of pcre_compile() */ - pe, /* result of pcre_study(), or NULL */ - PCRE_INFO_SIZE, /* what is required */ - &length); /* where to put the data */ -- -
-The possible values for the third argument are defined in pcre.h, and are -as follows: -
--
- PCRE_INFO_BACKREFMAX -- -
-Return the number of the highest back reference in the pattern. The fourth -argument should point to an int variable. Zero is returned if there are -no back references. -
--
- PCRE_INFO_CAPTURECOUNT -- -
-Return the number of capturing subpatterns in the pattern. The fourth argument -should point to an \fbint\fR variable. -
--
- PCRE_INFO_FIRSTBYTE -- -
-Return information about the first byte of any matched string, for a -non-anchored pattern. (This option used to be called PCRE_INFO_FIRSTCHAR; the -old name is still recognized for backwards compatibility.) -
--If there is a fixed first byte, e.g. from a pattern such as (cat|cow|coyote), -it is returned in the integer pointed to by where. Otherwise, if either -
--(a) the pattern was compiled with the PCRE_MULTILINE option, and every branch -starts with "^", or -
--(b) every branch of the pattern starts with ".*" and PCRE_DOTALL is not set -(if it were set, the pattern would be anchored), -
---1 is returned, indicating that the pattern matches only at the start of a -subject string or after any newline within the string. Otherwise -2 is -returned. For anchored patterns, -2 is returned. -
--
- PCRE_INFO_FIRSTTABLE -- -
-If the pattern was studied, and this resulted in the construction of a 256-bit -table indicating a fixed set of bytes for the first byte in any matching -string, a pointer to the table is returned. Otherwise NULL is returned. The -fourth argument should point to an unsigned char * variable. -
--
- PCRE_INFO_LASTLITERAL -- -
-Return the value of the rightmost literal byte that must exist in any matched -string, other than at its start, if such a byte has been recorded. The fourth -argument should point to an int variable. If there is no such byte, -1 is -returned. For anchored patterns, a last literal byte is recorded only if it -follows something of variable length. For example, for the pattern -/^a\d+z\d+/ the returned value is "z", but for /^a\dz\d/ the returned value -is -1. -
--
- PCRE_INFO_NAMECOUNT - PCRE_INFO_NAMEENTRYSIZE - PCRE_INFO_NAMETABLE -- -
-PCRE supports the use of named as well as numbered capturing parentheses. The -names are just an additional way of identifying the parentheses, which still -acquire a number. A caller that wants to extract data from a named subpattern -must convert the name to a number in order to access the correct pointers in -the output vector (described with pcre_exec() below). In order to do -this, it must first use these three values to obtain the name-to-number mapping -table for the pattern. -
--The map consists of a number of fixed-size entries. PCRE_INFO_NAMECOUNT gives -the number of entries, and PCRE_INFO_NAMEENTRYSIZE gives the size of each -entry; both of these return an int value. The entry size depends on the -length of the longest name. PCRE_INFO_NAMETABLE returns a pointer to the first -entry of the table (a pointer to char). The first two bytes of each entry -are the number of the capturing parenthesis, most significant byte first. The -rest of the entry is the corresponding name, zero terminated. The names are in -alphabetical order. For example, consider the following pattern (assume -PCRE_EXTENDED is set, so white space - including newlines - is ignored): -
--
- (?P<date> (?P<year>(\d\d)?\d\d) - - (?P<month>\d\d) - (?P<day>\d\d) ) -- -
-There are four named subpatterns, so the table has four entries, and each entry -in the table is eight bytes long. The table is as follows, with non-printing -bytes shows in hex, and undefined bytes shown as ??: -
--
- 00 01 d a t e 00 ?? - 00 05 d a y 00 ?? ?? - 00 04 m o n t h 00 - 00 02 y e a r 00 ?? -- -
-When writing code to extract data from named subpatterns, remember that the -length of each entry may be different for each compiled pattern. -
--
- PCRE_INFO_OPTIONS -- -
-Return a copy of the options with which the pattern was compiled. The fourth -argument should point to an unsigned long int variable. These option bits -are those specified in the call to pcre_compile(), modified by any -top-level option settings within the pattern itself. -
--A pattern is automatically anchored by PCRE if all of its top-level -alternatives begin with one of the following: -
--
- ^ unless PCRE_MULTILINE is set - \A always - \G always - .* if PCRE_DOTALL is set and there are no back - references to the subpattern in which .* appears -- -
-For such patterns, the PCRE_ANCHORED bit is set in the options returned by -pcre_fullinfo(). -
--
- PCRE_INFO_SIZE -- -
-Return the size of the compiled pattern, that is, the value that was passed as -the argument to pcre_malloc() when PCRE was getting memory in which to -place the compiled data. The fourth argument should point to a size_t -variable. -
--
- PCRE_INFO_STUDYSIZE -- -
-Returns the size of the data block pointed to by the study_data field in -a pcre_extra block. That is, it is the value that was passed to -pcre_malloc() when PCRE was getting memory into which to place the data -created by pcre_study(). The fourth argument should point to a -size_t variable. -
--int pcre_info(const pcre *code, int *optptr, int -*firstcharptr); -
--The pcre_info() function is now obsolete because its interface is too -restrictive to return all the available data about a compiled pattern. New -programs should use pcre_fullinfo() instead. The yield of -pcre_info() is the number of capturing subpatterns, or one of the -following negative numbers: -
--
- PCRE_ERROR_NULL the argument code was NULL - PCRE_ERROR_BADMAGIC the "magic number" was not found -- -
-If the optptr argument is not NULL, a copy of the options with which the -pattern was compiled is placed in the integer it points to (see -PCRE_INFO_OPTIONS above). -
--If the pattern is not anchored and the firstcharptr argument is not NULL, -it is used to pass back information about the first character of any matched -string (see PCRE_INFO_FIRSTBYTE above). -
--int pcre_exec(const pcre *code, const pcre_extra *extra, -const char *subject, int length, int startoffset, -int options, int *ovector, int ovecsize); -
--The function pcre_exec() is called to match a subject string against a -pre-compiled pattern, which is passed in the code argument. If the -pattern has been studied, the result of the study should be passed in the -extra argument. -
--Here is an example of a simple call to pcre_exec(): -
--
- int rc; - int ovector[30]; - rc = pcre_exec( - re, /* result of pcre_compile() */ - NULL, /* we didn't study the pattern */ - "some string", /* the subject string */ - 11, /* the length of the subject string */ - 0, /* start at offset 0 in the subject */ - 0, /* default options */ - ovector, /* vector for substring information */ - 30); /* number of elements in the vector */ -- -
-If the extra argument is not NULL, it must point to a pcre_extra -data block. The pcre_study() function returns such a block (when it -doesn't return NULL), but you can also create one for yourself, and pass -additional information in it. The fields in the block are as follows: -
--
- unsigned long int flags; - void *study_data; - unsigned long int match_limit; - void *callout_data; -- -
-The flags field is a bitmap that specifies which of the other fields -are set. The flag bits are: -
--
- PCRE_EXTRA_STUDY_DATA - PCRE_EXTRA_MATCH_LIMIT - PCRE_EXTRA_CALLOUT_DATA -- -
-Other flag bits should be set to zero. The study_data field is set in the -pcre_extra block that is returned by pcre_study(), together with -the appropriate flag bit. You should not set this yourself, but you can add to -the block by setting the other fields. -
--The match_limit field provides a means of preventing PCRE from using up a -vast amount of resources when running patterns that are not going to match, -but which have a very large number of possibilities in their search trees. The -classic example is the use of nested unlimited repeats. Internally, PCRE uses a -function called match() which it calls repeatedly (sometimes -recursively). The limit is imposed on the number of times this function is -called during a match, which has the effect of limiting the amount of recursion -and backtracking that can take place. For patterns that are not anchored, the -count starts from zero for each position in the subject string. -
--The default limit for the library can be set when PCRE is built; the default -default is 10 million, which handles all but the most extreme cases. You can -reduce the default by suppling pcre_exec() with a \fRpcre_extra\fR block -in which match_limit is set to a smaller value, and -PCRE_EXTRA_MATCH_LIMIT is set in the flags field. If the limit is -exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT. -
--The pcre_callout field is used in conjunction with the "callout" feature, -which is described in the pcrecallout documentation. -
--The PCRE_ANCHORED option can be passed in the options argument, whose -unused bits must be zero. This limits pcre_exec() to matching at the -first matching position. However, if a pattern was compiled with PCRE_ANCHORED, -or turned out to be anchored by virtue of its contents, it cannot be made -unachored at matching time. -
--When PCRE_UTF8 was set at compile time, the validity of the subject as a UTF-8 -string is automatically checked, and the value of startoffset is also -checked to ensure that it points to the start of a UTF-8 character. If an -invalid UTF-8 sequence of bytes is found, pcre_exec() returns the error -PCRE_ERROR_BADUTF8. If startoffset contains an invalid value, -PCRE_ERROR_BADUTF8_OFFSET is returned. -
--If you already know that your subject is valid, and you want to skip these -checks for performance reasons, you can set the PCRE_NO_UTF8_CHECK option when -calling pcre_exec(). You might want to do this for the second and -subsequent calls to pcre_exec() if you are making repeated calls to find -all the matches in a single subject string. However, you should be sure that -the value of startoffset points to the start of a UTF-8 character. When -PCRE_NO_UTF8_CHECK is set, the effect of passing an invalid UTF-8 string as a -subject, or a value of startoffset that does not point to the start of a -UTF-8 character, is undefined. Your program may crash. -
--There are also three further options that can be set only at matching time: -
--
- PCRE_NOTBOL -- -
-The first character of the string is not the beginning of a line, so the -circumflex metacharacter should not match before it. Setting this without -PCRE_MULTILINE (at compile time) causes circumflex never to match. -
--
- PCRE_NOTEOL -- -
-The end of the string is not the end of a line, so the dollar metacharacter -should not match it nor (except in multiline mode) a newline immediately before -it. Setting this without PCRE_MULTILINE (at compile time) causes dollar never -to match. -
--
- PCRE_NOTEMPTY -- -
-An empty string is not considered to be a valid match if this option is set. If -there are alternatives in the pattern, they are tried. If all the alternatives -match the empty string, the entire match fails. For example, if the pattern -
--
- a?b? -- -
-is applied to a string not beginning with "a" or "b", it matches the empty -string at the start of the subject. With PCRE_NOTEMPTY set, this match is not -valid, so PCRE searches further into the string for occurrences of "a" or "b". -
--Perl has no direct equivalent of PCRE_NOTEMPTY, but it does make a special case -of a pattern match of the empty string within its split() function, and -when using the /g modifier. It is possible to emulate Perl's behaviour after -matching a null string by first trying the match again at the same offset with -PCRE_NOTEMPTY set, and then if that fails by advancing the starting offset (see -below) and trying an ordinary match again. -
--The subject string is passed to pcre_exec() as a pointer in -subject, a length in length, and a starting byte offset in -startoffset. Unlike the pattern string, the subject may contain binary -zero bytes. When the starting offset is zero, the search for a match starts at -the beginning of the subject, and this is by far the most common case. -
--If the pattern was compiled with the PCRE_UTF8 option, the subject must be a -sequence of bytes that is a valid UTF-8 string, and the starting offset must -point to the beginning of a UTF-8 character. If an invalid UTF-8 string or -offset is passed, an error (either PCRE_ERROR_BADUTF8 or -PCRE_ERROR_BADUTF8_OFFSET) is returned, unless the option PCRE_NO_UTF8_CHECK is -set, in which case PCRE's behaviour is not defined. -
--A non-zero starting offset is useful when searching for another match in the -same subject by calling pcre_exec() again after a previous success. -Setting startoffset differs from just passing over a shortened string and -setting PCRE_NOTBOL in the case of a pattern that begins with any kind of -lookbehind. For example, consider the pattern -
--
- \Biss\B -- -
-which finds occurrences of "iss" in the middle of words. (\B matches only if -the current position in the subject is not a word boundary.) When applied to -the string "Mississipi" the first call to pcre_exec() finds the first -occurrence. If pcre_exec() is called again with just the remainder of the -subject, namely "issipi", it does not match, because \B is always false at the -start of the subject, which is deemed to be a word boundary. However, if -pcre_exec() is passed the entire string again, but with startoffset -set to 4, it finds the second occurrence of "iss" because it is able to look -behind the starting point to discover that it is preceded by a letter. -
--If a non-zero starting offset is passed when the pattern is anchored, one -attempt to match at the given offset is tried. This can only succeed if the -pattern does not require the match to be at the start of the subject. -
--In general, a pattern matches a certain portion of the subject, and in -addition, further substrings from the subject may be picked out by parts of the -pattern. Following the usage in Jeffrey Friedl's book, this is called -"capturing" in what follows, and the phrase "capturing subpattern" is used for -a fragment of a pattern that picks out a substring. PCRE supports several other -kinds of parenthesized subpattern that do not cause substrings to be captured. -
--Captured substrings are returned to the caller via a vector of integer offsets -whose address is passed in ovector. The number of elements in the vector -is passed in ovecsize. The first two-thirds of the vector is used to pass -back captured substrings, each substring using a pair of integers. The -remaining third of the vector is used as workspace by pcre_exec() while -matching capturing subpatterns, and is not available for passing back -information. The length passed in ovecsize should always be a multiple of -three. If it is not, it is rounded down. -
--When a match has been successful, information about captured substrings is -returned in pairs of integers, starting at the beginning of ovector, and -continuing up to two-thirds of its length at the most. The first element of a -pair is set to the offset of the first character in a substring, and the second -is set to the offset of the first character after the end of a substring. The -first pair, ovector[0] and ovector[1], identify the portion of the -subject string matched by the entire pattern. The next pair is used for the -first capturing subpattern, and so on. The value returned by pcre_exec() -is the number of pairs that have been set. If there are no capturing -subpatterns, the return value from a successful match is 1, indicating that -just the first pair of offsets has been set. -
--Some convenience functions are provided for extracting the captured substrings -as separate strings. These are described in the following section. -
--It is possible for an capturing subpattern number n+1 to match some -part of the subject when subpattern n has not been used at all. For -example, if the string "abc" is matched against the pattern (a|(z))(bc) -subpatterns 1 and 3 are matched, but 2 is not. When this happens, both offset -values corresponding to the unused subpattern are set to -1. -
--If a capturing subpattern is matched repeatedly, it is the last portion of the -string that it matched that gets returned. -
--If the vector is too small to hold all the captured substrings, it is used as -far as possible (up to two-thirds of its length), and the function returns a -value of zero. In particular, if the substring offsets are not of interest, -pcre_exec() may be called with ovector passed as NULL and -ovecsize as zero. However, if the pattern contains back references and -the ovector isn't big enough to remember the related substrings, PCRE has -to get additional memory for use during matching. Thus it is usually advisable -to supply an ovector. -
--Note that pcre_info() can be used to find out how many capturing -subpatterns there are in a compiled pattern. The smallest size for -ovector that will allow for n captured substrings, in addition to -the offsets of the substring matched by the whole pattern, is (n+1)*3. -
--If pcre_exec() fails, it returns a negative number. The following are -defined in the header file: -
--
- PCRE_ERROR_NOMATCH (-1) -- -
-The subject string did not match the pattern. -
--
- PCRE_ERROR_NULL (-2) -- -
-Either code or subject was passed as NULL, or ovector was -NULL and ovecsize was not zero. -
--
- PCRE_ERROR_BADOPTION (-3) -- -
-An unrecognized bit was set in the options argument. -
--
- PCRE_ERROR_BADMAGIC (-4) -- -
-PCRE stores a 4-byte "magic number" at the start of the compiled code, to catch -the case when it is passed a junk pointer. This is the error it gives when the -magic number isn't present. -
--
- PCRE_ERROR_UNKNOWN_NODE (-5) -- -
-While running the pattern match, an unknown item was encountered in the -compiled pattern. This error could be caused by a bug in PCRE or by overwriting -of the compiled pattern. -
--
- PCRE_ERROR_NOMEMORY (-6) -- -
-If a pattern contains back references, but the ovector that is passed to -pcre_exec() is not big enough to remember the referenced substrings, PCRE -gets a block of memory at the start of matching to use for this purpose. If the -call via pcre_malloc() fails, this error is given. The memory is freed at -the end of matching. -
--
- PCRE_ERROR_NOSUBSTRING (-7) -- -
-This error is used by the pcre_copy_substring(), -pcre_get_substring(), and pcre_get_substring_list() functions (see -below). It is never returned by pcre_exec(). -
--
- PCRE_ERROR_MATCHLIMIT (-8) -- -
-The recursion and backtracking limit, as specified by the match_limit -field in a pcre_extra structure (or defaulted) was reached. See the -description above. -
--
- PCRE_ERROR_CALLOUT (-9) -- -
-This error is never generated by pcre_exec() itself. It is provided for -use by callout functions that want to yield a distinctive error code. See the -pcrecallout documentation for details. -
--
- PCRE_ERROR_BADUTF8 (-10) -- -
-A string that contains an invalid UTF-8 byte sequence was passed as a subject. -
--
- PCRE_ERROR_BADUTF8_OFFSET (-11) -- -
-The UTF-8 byte sequence that was passed as a subject was valid, but the value -of startoffset did not point to the beginning of a UTF-8 character. -
--int pcre_copy_substring(const char *subject, int *ovector, -int stringcount, int stringnumber, char *buffer, -int buffersize); -
--int pcre_get_substring(const char *subject, int *ovector, -int stringcount, int stringnumber, -const char **stringptr); -
--int pcre_get_substring_list(const char *subject, -int *ovector, int stringcount, const char ***listptr); -
--Captured substrings can be accessed directly by using the offsets returned by -pcre_exec() in ovector. For convenience, the functions -pcre_copy_substring(), pcre_get_substring(), and -pcre_get_substring_list() are provided for extracting captured substrings -as new, separate, zero-terminated strings. These functions identify substrings -by number. The next section describes functions for extracting named -substrings. A substring that contains a binary zero is correctly extracted and -has a further zero added on the end, but the result is not, of course, -a C string. -
--The first three arguments are the same for all three of these functions: -subject is the subject string which has just been successfully matched, -ovector is a pointer to the vector of integer offsets that was passed to -pcre_exec(), and stringcount is the number of substrings that were -captured by the match, including the substring that matched the entire regular -expression. This is the value returned by pcre_exec if it is greater than -zero. If pcre_exec() returned zero, indicating that it ran out of space -in ovector, the value passed as stringcount should be the size of -the vector divided by three. -
--The functions pcre_copy_substring() and pcre_get_substring() -extract a single substring, whose number is given as stringnumber. A -value of zero extracts the substring that matched the entire pattern, while -higher values extract the captured substrings. For pcre_copy_substring(), -the string is placed in buffer, whose length is given by -buffersize, while for pcre_get_substring() a new block of memory is -obtained via pcre_malloc, and its address is returned via -stringptr. The yield of the function is the length of the string, not -including the terminating zero, or one of -
--
- PCRE_ERROR_NOMEMORY (-6) -- -
-The buffer was too small for pcre_copy_substring(), or the attempt to get -memory failed for pcre_get_substring(). -
--
- PCRE_ERROR_NOSUBSTRING (-7) -- -
-There is no substring whose number is stringnumber. -
--The pcre_get_substring_list() function extracts all available substrings -and builds a list of pointers to them. All this is done in a single block of -memory which is obtained via pcre_malloc. The address of the memory block -is returned via listptr, which is also the start of the list of string -pointers. The end of the list is marked by a NULL pointer. The yield of the -function is zero if all went well, or -
--
- PCRE_ERROR_NOMEMORY (-6) -- -
-if the attempt to get the memory block failed. -
--When any of these functions encounter a substring that is unset, which can -happen when capturing subpattern number n+1 matches some part of the -subject, but subpattern n has not been used at all, they return an empty -string. This can be distinguished from a genuine zero-length substring by -inspecting the appropriate offset in ovector, which is negative for unset -substrings. -
--The two convenience functions pcre_free_substring() and -pcre_free_substring_list() can be used to free the memory returned by -a previous call of pcre_get_substring() or -pcre_get_substring_list(), respectively. They do nothing more than call -the function pointed to by pcre_free, which of course could be called -directly from a C program. However, PCRE is used in some situations where it is -linked via a special interface to another programming language which cannot use -pcre_free directly; it is for these cases that the functions are -provided. -
--int pcre_copy_named_substring(const pcre *code, -const char *subject, int *ovector, -int stringcount, const char *stringname, -char *buffer, int buffersize); -
--int pcre_get_stringnumber(const pcre *code, -const char *name); -
--int pcre_get_named_substring(const pcre *code, -const char *subject, int *ovector, -int stringcount, const char *stringname, -const char **stringptr); -
--To extract a substring by name, you first have to find associated number. This -can be done by calling pcre_get_stringnumber(). The first argument is the -compiled pattern, and the second is the name. For example, for this pattern -
--
- ab(?<xxx>\d+)... -- -
-the number of the subpattern called "xxx" is 1. Given the number, you can then -extract the substring directly, or use one of the functions described in the -previous section. For convenience, there are also two functions that do the -whole job. -
--Most of the arguments of pcre_copy_named_substring() and -pcre_get_named_substring() are the same as those for the functions that -extract by number, and so are not re-described here. There are just two -differences. -
--First, instead of a substring number, a substring name is given. Second, there -is an extra argument, given at the start, which is a pointer to the compiled -pattern. This is needed in order to gain access to the name-to-number -translation table. -
--These functions call pcre_get_stringnumber(), and if it succeeds, they -then call pcre_copy_substring() or pcre_get_substring(), as -appropriate. -
-
-Last updated: 09 December 2003
-
-Copyright © 1997-2003 University of Cambridge.
diff --git a/external-libs/pcre/doc/html/pcrebuild.html b/external-libs/pcre/doc/html/pcrebuild.html
deleted file mode 100644
index c70f8221..00000000
--- a/external-libs/pcre/doc/html/pcrebuild.html
+++ /dev/null
@@ -1,189 +0,0 @@
-
-
-This document describes the optional features of PCRE that can be selected when -the library is compiled. They are all selected, or deselected, by providing -options to the configure script which is run before the make -command. The complete list of options for configure (which includes the -standard ones such as the selection of the installation directory) can be -obtained by running -
--
- ./configure --help -- -
-The following sections describe certain options whose names begin with --enable -or --disable. These settings specify changes to the defaults for the -configure command. Because of the way that configure works, ---enable and --disable always come in pairs, so the complementary option always -exists as well, but as it specifies the default, it is not described. -
--To build PCRE with support for UTF-8 character strings, add -
--
- --enable-utf8 -- -
-to the configure command. Of itself, this does not make PCRE treat -strings as UTF-8. As well as compiling PCRE with this option, you also have -have to set the PCRE_UTF8 option when you call the pcre_compile() -function. -
--By default, PCRE treats character 10 (linefeed) as the newline character. This -is the normal newline character on Unix-like systems. You can compile PCRE to -use character 13 (carriage return) instead by adding -
--
- --enable-newline-is-cr -- -
-to the configure command. For completeness there is also a ---enable-newline-is-lf option, which explicitly specifies linefeed as the -newline character. -
--The PCRE building process uses libtool to build both shared and static -Unix libraries by default. You can suppress one of these by adding one of -
--
- --disable-shared - --disable-static -- -
-to the configure command, as required. -
--When PCRE is called through the POSIX interface (see the pcreposix -documentation), additional working storage is required for holding the pointers -to capturing substrings because PCRE requires three integers per substring, -whereas the POSIX interface provides only two. If the number of expected -substrings is small, the wrapper function uses space on the stack, because this -is faster than using malloc() for each call. The default threshold above -which the stack is no longer used is 10; it can be changed by adding a setting -such as -
--
- --with-posix-malloc-threshold=20 -- -
-to the configure command. -
--Internally, PCRE has a function called match() which it calls repeatedly -(possibly recursively) when performing a matching operation. By limiting the -number of times this function may be called, a limit can be placed on the -resources used by a single call to pcre_exec(). The limit can be changed -at run time, as described in the pcreapi documentation. The default is 10 -million, but this can be changed by adding a setting such as -
--
- --with-match-limit=500000 -- -
-to the configure command. -
--Within a compiled pattern, offset values are used to point from one part to -another (for example, from an opening parenthesis to an alternation -metacharacter). By default two-byte values are used for these offsets, leading -to a maximum size for a compiled pattern of around 64K. This is sufficient to -handle all but the most gigantic patterns. Nevertheless, some people do want to -process enormous patterns, so it is possible to compile PCRE to use three-byte -or four-byte offsets by adding a setting such as -
--
- --with-link-size=3 -- -
-to the configure command. The value given must be 2, 3, or 4. Using -longer offsets slows down the operation of PCRE because it has to load -additional bytes when handling them. -
--If you build PCRE with an increased link size, test 2 (and test 5 if you are -using UTF-8) will fail. Part of the output of these tests is a representation -of the compiled pattern, and this changes with the link size. -
--PCRE implements backtracking while matching by making recursive calls to an -internal function called match(). In environments where the size of the -stack is limited, this can severely limit PCRE's operation. (The Unix -environment does not usually suffer from this problem.) An alternative approach -that uses memory from the heap to remember data, instead of using recursive -function calls, has been implemented to work round this problem. If you want to -build a version of PCRE that works this way, add -
--
- --disable-stack-for-recursion -- -
-to the configure command. With this configuration, PCRE will use the -pcre_stack_malloc and pcre_stack_free variables to call memory -management functions. Separate functions are provided because the usage is very -predictable: the block sizes requested are always the same, and the blocks are -always freed in reverse order. A calling program might be able to implement -optimized functions that perform better than the standard malloc() and -free() functions. PCRE runs noticeably more slowly when built in this -way. -
--PCRE assumes by default that it will run in an environment where the character -code is ASCII (or UTF-8, which is a superset of ASCII). PCRE can, however, be -compiled to run in an EBCDIC environment by adding -
--
- --enable-ebcdic -- -
-to the configure command. -
-
-Last updated: 09 December 2003
-
-Copyright © 1997-2003 University of Cambridge.
diff --git a/external-libs/pcre/doc/html/pcrecallout.html b/external-libs/pcre/doc/html/pcrecallout.html
deleted file mode 100644
index f4b7104e..00000000
--- a/external-libs/pcre/doc/html/pcrecallout.html
+++ /dev/null
@@ -1,117 +0,0 @@
-
-
-int (*pcre_callout)(pcre_callout_block *); -
--PCRE provides a feature called "callout", which is a means of temporarily -passing control to the caller of PCRE in the middle of pattern matching. The -caller of PCRE provides an external function by putting its entry point in the -global variable pcre_callout. By default, this variable contains NULL, -which disables all calling out. -
--Within a regular expression, (?C) indicates the points at which the external -function is to be called. Different callout points can be identified by putting -a number less than 256 after the letter C. The default value is zero. -For example, this pattern has two callout points: -
--
- (?C1)\dabc(?C2)def -- -
-During matching, when PCRE reaches a callout point (and pcre_callout is -set), the external function is called. Its only argument is a pointer to a -pcre_callout block. This contains the following variables: -
--
- int version; - int callout_number; - int *offset_vector; - const char *subject; - int subject_length; - int start_match; - int current_position; - int capture_top; - int capture_last; - void *callout_data; -- -
-The version field is an integer containing the version number of the -block format. The current version is zero. The version number may change in -future if additional fields are added, but the intention is never to remove any -of the existing fields. -
--The callout_number field contains the number of the callout, as compiled -into the pattern (that is, the number after ?C). -
--The offset_vector field is a pointer to the vector of offsets that was -passed by the caller to pcre_exec(). The contents can be inspected in -order to extract substrings that have been matched so far, in the same way as -for extracting substrings after a match has completed. -
--The subject and subject_length fields contain copies the values -that were passed to pcre_exec(). -
--The start_match field contains the offset within the subject at which the -current match attempt started. If the pattern is not anchored, the callout -function may be called several times for different starting points. -
--The current_position field contains the offset within the subject of the -current match pointer. -
--The capture_top field contains one more than the number of the highest -numbered captured substring so far. If no substrings have been captured, -the value of capture_top is one. -
--The capture_last field contains the number of the most recently captured -substring. -
--The callout_data field contains a value that is passed to -pcre_exec() by the caller specifically so that it can be passed back in -callouts. It is passed in the pcre_callout field of the pcre_extra -data structure. If no such data was passed, the value of callout_data in -a pcre_callout block is NULL. There is a description of the -pcre_extra structure in the pcreapi documentation. -
--The callout function returns an integer. If the value is zero, matching -proceeds as normal. If the value is greater than zero, matching fails at the -current point, but backtracking to test other possibilities goes ahead, just as -if a lookahead assertion had failed. If the value is less than zero, the match -is abandoned, and pcre_exec() returns the value. -
--Negative values should normally be chosen from the set of PCRE_ERROR_xxx -values. In particular, PCRE_ERROR_NOMATCH forces a standard "no match" failure. -The error number PCRE_ERROR_CALLOUT is reserved for use by callout functions; -it will never be used by PCRE itself. -
-
-Last updated: 21 January 2003
-
-Copyright © 1997-2003 University of Cambridge.
diff --git a/external-libs/pcre/doc/html/pcrecompat.html b/external-libs/pcre/doc/html/pcrecompat.html
deleted file mode 100644
index 1ec22038..00000000
--- a/external-libs/pcre/doc/html/pcrecompat.html
+++ /dev/null
@@ -1,136 +0,0 @@
-
-
-This document describes the differences in the ways that PCRE and Perl handle -regular expressions. The differences described here are with respect to Perl -5.8. -
--1. PCRE does not have full UTF-8 support. Details of what it does have are -given in the -section on UTF-8 support -in the main -pcre -page. -
--2. PCRE does not allow repeat quantifiers on lookahead assertions. Perl permits -them, but they do not mean what you might think. For example, (?!a){3} does -not assert that the next three characters are not "a". It just asserts that the -next character is not "a" three times. -
--3. Capturing subpatterns that occur inside negative lookahead assertions are -counted, but their entries in the offsets vector are never set. Perl sets its -numerical variables from any such patterns that are matched before the -assertion fails to match something (thereby succeeding), but only if the -negative lookahead assertion contains just one branch. -
--4. Though binary zero characters are supported in the subject string, they are -not allowed in a pattern string because it is passed as a normal C string, -terminated by zero. The escape sequence "\0" can be used in the pattern to -represent a binary zero. -
--5. The following Perl escape sequences are not supported: \l, \u, \L, -\U, \P, \p, \N, and \X. In fact these are implemented by Perl's general -string-handling and are not part of its pattern matching engine. If any of -these are encountered by PCRE, an error is generated. -
--6. PCRE does support the \Q...\E escape for quoting substrings. Characters in -between are treated as literals. This is slightly different from Perl in that $ -and @ are also handled as literals inside the quotes. In Perl, they cause -variable interpolation (but of course PCRE does not have variables). Note the -following examples: -
--
- Pattern PCRE matches Perl matches -- -
-
- \Qabc$xyz\E abc$xyz abc followed by the - contents of $xyz - \Qabc\$xyz\E abc\$xyz abc\$xyz - \Qabc\E\$\Qxyz\E abc$xyz abc$xyz -- -
-The \Q...\E sequence is recognized both inside and outside character classes. -
--7. Fairly obviously, PCRE does not support the (?{code}) and (?p{code}) -constructions. However, there is some experimental support for recursive -patterns using the non-Perl items (?R), (?number) and (?P>name). Also, the PCRE -"callout" feature allows an external function to be called during pattern -matching. -
--8. There are some differences that are concerned with the settings of captured -strings when part of a pattern is repeated. For example, matching "aba" against -the pattern /^(a(b)?)+$/ in Perl leaves $2 unset, but in PCRE it is set to "b". -
--9. PCRE provides some extensions to the Perl regular expression facilities: -
--(a) Although lookbehind assertions must match fixed length strings, each -alternative branch of a lookbehind assertion can match a different length of -string. Perl requires them all to have the same length. -
--(b) If PCRE_DOLLAR_ENDONLY is set and PCRE_MULTILINE is not set, the $ -meta-character matches only at the very end of the string. -
--© If PCRE_EXTRA is set, a backslash followed by a letter with no special -meaning is faulted. -
--(d) If PCRE_UNGREEDY is set, the greediness of the repetition quantifiers is -inverted, that is, by default they are not greedy, but if followed by a -question mark they are. -
--(e) PCRE_ANCHORED can be used to force a pattern to be tried only at the first -matching position in the subject string. -
--(f) The PCRE_NOTBOL, PCRE_NOTEOL, PCRE_NOTEMPTY, and PCRE_NO_AUTO_CAPTURE -options for pcre_exec() have no Perl equivalents. -
--(g) The (?R), (?number), and (?P>name) constructs allows for recursive pattern -matching (Perl can do this using the (?p{code}) construct, which PCRE cannot -support.) -
--(h) PCRE supports named capturing substrings, using the Python syntax. -
--(i) PCRE supports the possessive quantifier "++" syntax, taken from Sun's Java -package. -
--(j) The (R) condition, for testing recursion, is a PCRE extension. -
--(k) The callout facility is PCRE-specific. -
-
-Last updated: 09 December 2003
-
-Copyright © 1997-2003 University of Cambridge.
diff --git a/external-libs/pcre/doc/html/pcregrep.html b/external-libs/pcre/doc/html/pcregrep.html
deleted file mode 100644
index a76cac21..00000000
--- a/external-libs/pcre/doc/html/pcregrep.html
+++ /dev/null
@@ -1,153 +0,0 @@
-
-
-pcregrep [-Vcfhilnrsuvx] [long options] [pattern] [file1 file2 ...] -
--pcregrep searches files for character patterns, in the same way as other -grep commands do, but it uses the PCRE regular expression library to support -patterns that are compatible with the regular expressions of Perl 5. See -pcrepattern -for a full description of syntax and semantics of the regular expressions that -PCRE supports. -
--A pattern must be specified on the command line unless the -f option is -used (see below). -
--If no files are specified, pcregrep reads the standard input. By default, -each line that matches the pattern is copied to the standard output, and if -there is more than one file, the file name is printed before each line of -output. However, there are options that can change how pcregrep behaves. -
--Lines are limited to BUFSIZ characters. BUFSIZ is defined in <stdio.h>. -The newline character is removed from the end of each line before it is matched -against the pattern. -
---V -Write the version number of the PCRE library being used to the standard error -stream. -
---c -Do not print individual lines; instead just print a count of the number of -lines that would otherwise have been printed. If several files are given, a -count is printed for each of them. -
---ffilename -Read a number of patterns from the file, one per line, and match all of them -against each line of input. A line is output if any of the patterns match it. -When -f is used, no pattern is taken from the command line; all arguments -are treated as file names. There is a maximum of 100 patterns. Trailing white -space is removed, and blank lines are ignored. An empty file contains no -patterns and therefore matches nothing. -
---h -Suppress printing of filenames when searching multiple files. -
---i -Ignore upper/lower case distinctions during comparisons. -
---l -Instead of printing lines from the files, just print the names of the files -containing lines that would have been printed. Each file name is printed -once, on a separate line. -
---n -Precede each line by its line number in the file. -
---r -If any file is a directory, recursively scan the files it contains. Without --r a directory is scanned as a normal file. -
---s -Work silently, that is, display nothing except error messages. -The exit status indicates whether any matches were found. -
---u -Operate in UTF-8 mode. This option is available only if PCRE has been compiled -with UTF-8 support. Both the pattern and each subject line are assumed to be -valid strings of UTF-8 characters. -
---v -Invert the sense of the match, so that lines which do not match the -pattern are now the ones that are found. -
---x -Force the pattern to be anchored (it must start matching at the beginning of -the line) and in addition, require it to match the entire line. This is -equivalent to having ^ and $ characters at the start and end of each -alternative branch in the regular expression. -
--Long forms of all the options are available, as in GNU grep. They are shown in -the following table: -
--
- -c --count - -h --no-filename - -i --ignore-case - -l --files-with-matches - -n --line-number - -r --recursive - -s --no-messages - -u --utf-8 - -V --version - -v --invert-match - -x --line-regex - -x --line-regexp -- -
-In addition, --file=filename is equivalent to -ffilename, and ---help shows the list of options and then exits. -
--Exit status is 0 if any matches were found, 1 if no matches were found, and 2 -for syntax errors or inacessible files (even if matches were found). -
-
-Philip Hazel <ph10@cam.ac.uk>
-
-University Computing Service
-
-Cambridge CB2 3QG, England.
-
-Last updated: 03 February 2003
-
-Copyright © 1997-2003 University of Cambridge.
diff --git a/external-libs/pcre/doc/html/pcrepattern.html b/external-libs/pcre/doc/html/pcrepattern.html
deleted file mode 100644
index 65abcc21..00000000
--- a/external-libs/pcre/doc/html/pcrepattern.html
+++ /dev/null
@@ -1,1607 +0,0 @@
-
-
-The syntax and semantics of the regular expressions supported by PCRE are -described below. Regular expressions are also described in the Perl -documentation and in a number of other books, some of which have copious -examples. Jeffrey Friedl's "Mastering Regular Expressions", published by -O'Reilly, covers them in great detail. The description here is intended as -reference documentation. -
--The basic operation of PCRE is on strings of bytes. However, there is also -support for UTF-8 character strings. To use this support you must build PCRE to -include UTF-8 support, and then call pcre_compile() with the PCRE_UTF8 -option. How this affects the pattern matching is mentioned in several places -below. There is also a summary of UTF-8 features in the -section on UTF-8 support -in the main -pcre -page. -
--A regular expression is a pattern that is matched against a subject string from -left to right. Most characters stand for themselves in a pattern, and match the -corresponding characters in the subject. As a trivial example, the pattern -
--
- The quick brown fox -- -
-matches a portion of a subject string that is identical to itself. The power of -regular expressions comes from the ability to include alternatives and -repetitions in the pattern. These are encoded in the pattern by the use of -meta-characters, which do not stand for themselves but instead are -interpreted in some special way. -
--There are two different sets of meta-characters: those that are recognized -anywhere in the pattern except within square brackets, and those that are -recognized in square brackets. Outside square brackets, the meta-characters are -as follows: -
--
- \ general escape character with several uses - ^ assert start of string (or line, in multiline mode) - $ assert end of string (or line, in multiline mode) - . match any character except newline (by default) - [ start character class definition - | start of alternative branch - ( start subpattern - ) end subpattern - ? extends the meaning of ( - also 0 or 1 quantifier - also quantifier minimizer - * 0 or more quantifier - + 1 or more quantifier - also "possessive quantifier" - { start min/max quantifier -- -
-Part of a pattern that is in square brackets is called a "character class". In -a character class the only meta-characters are: -
--
- \ general escape character - ^ negate the class, but only if the first character - - indicates character range - [ POSIX character class (only if followed by POSIX - syntax) - ] terminates the character class -- -
-The following sections describe the use of each of the meta-characters. -
--The backslash character has several uses. Firstly, if it is followed by a -non-alphameric character, it takes away any special meaning that character may -have. This use of backslash as an escape character applies both inside and -outside character classes. -
--For example, if you want to match a * character, you write \* in the pattern. -This escaping action applies whether or not the following character would -otherwise be interpreted as a meta-character, so it is always safe to precede a -non-alphameric with backslash to specify that it stands for itself. In -particular, if you want to match a backslash, you write \\. -
--If a pattern is compiled with the PCRE_EXTENDED option, whitespace in the -pattern (other than in a character class) and characters between a # outside -a character class and the next newline character are ignored. An escaping -backslash can be used to include a whitespace or # character as part of the -pattern. -
--If you want to remove the special meaning from a sequence of characters, you -can do so by putting them between \Q and \E. This is different from Perl in -that $ and @ are handled as literals in \Q...\E sequences in PCRE, whereas in -Perl, $ and @ cause variable interpolation. Note the following examples: -
--
- Pattern PCRE matches Perl matches -- -
-
- \Qabc$xyz\E abc$xyz abc followed by the - contents of $xyz - \Qabc\$xyz\E abc\$xyz abc\$xyz - \Qabc\E\$\Qxyz\E abc$xyz abc$xyz -- -
-The \Q...\E sequence is recognized both inside and outside character classes. -
--A second use of backslash provides a way of encoding non-printing characters -in patterns in a visible manner. There is no restriction on the appearance of -non-printing characters, apart from the binary zero that terminates a pattern, -but when a pattern is being prepared by text editing, it is usually easier to -use one of the following escape sequences than the binary character it -represents: -
--
- \a alarm, that is, the BEL character (hex 07) - \cx "control-x", where x is any character - \e escape (hex 1B) - \f formfeed (hex 0C) - \n newline (hex 0A) - \r carriage return (hex 0D) - \t tab (hex 09) - \ddd character with octal code ddd, or backreference - \xhh character with hex code hh - \x{hhh..} character with hex code hhh... (UTF-8 mode only) -- -
-The precise effect of \cx is as follows: if x is a lower case letter, it -is converted to upper case. Then bit 6 of the character (hex 40) is inverted. -Thus \cz becomes hex 1A, but \c{ becomes hex 3B, while \c; becomes hex -7B. -
--After \x, from zero to two hexadecimal digits are read (letters can be in -upper or lower case). In UTF-8 mode, any number of hexadecimal digits may -appear between \x{ and }, but the value of the character code must be less -than 2**31 (that is, the maximum hexadecimal value is 7FFFFFFF). If characters -other than hexadecimal digits appear between \x{ and }, or if there is no -terminating }, this form of escape is not recognized. Instead, the initial -\x will be interpreted as a basic hexadecimal escape, with no following -digits, giving a byte whose value is zero. -
--Characters whose value is less than 256 can be defined by either of the two -syntaxes for \x when PCRE is in UTF-8 mode. There is no difference in the -way they are handled. For example, \xdc is exactly the same as \x{dc}. -
--After \0 up to two further octal digits are read. In both cases, if there -are fewer than two digits, just those that are present are used. Thus the -sequence \0\x\07 specifies two binary zeros followed by a BEL character -(code value 7). Make sure you supply two digits after the initial zero if the -character that follows is itself an octal digit. -
--The handling of a backslash followed by a digit other than 0 is complicated. -Outside a character class, PCRE reads it and any following digits as a decimal -number. If the number is less than 10, or if there have been at least that many -previous capturing left parentheses in the expression, the entire sequence is -taken as a back reference. A description of how this works is given -later, following the discussion of parenthesized subpatterns. -
--Inside a character class, or if the decimal number is greater than 9 and there -have not been that many capturing subpatterns, PCRE re-reads up to three octal -digits following the backslash, and generates a single byte from the least -significant 8 bits of the value. Any subsequent digits stand for themselves. -For example: -
--
- \040 is another way of writing a space - \40 is the same, provided there are fewer than 40 - previous capturing subpatterns - \7 is always a back reference - \11 might be a back reference, or another way of - writing a tab - \011 is always a tab - \0113 is a tab followed by the character "3" - \113 might be a back reference, otherwise the - character with octal code 113 - \377 might be a back reference, otherwise - the byte consisting entirely of 1 bits - \81 is either a back reference, or a binary zero - followed by the two characters "8" and "1" -- -
-Note that octal values of 100 or greater must not be introduced by a leading -zero, because no more than three octal digits are ever read. -
--All the sequences that define a single byte value or a single UTF-8 character -(in UTF-8 mode) can be used both inside and outside character classes. In -addition, inside a character class, the sequence \b is interpreted as the -backspace character (hex 08). Outside a character class it has a different -meaning (see below). -
--The third use of backslash is for specifying generic character types: -
--
- \d any decimal digit - \D any character that is not a decimal digit - \s any whitespace character - \S any character that is not a whitespace character - \w any "word" character - \W any "non-word" character -- -
-Each pair of escape sequences partitions the complete set of characters into -two disjoint sets. Any given character matches one, and only one, of each pair. -
--In UTF-8 mode, characters with values greater than 255 never match \d, \s, or -\w, and always match \D, \S, and \W. -
--For compatibility with Perl, \s does not match the VT character (code 11). -This makes it different from the the POSIX "space" class. The \s characters -are HT (9), LF (10), FF (12), CR (13), and space (32). -
--A "word" character is any letter or digit or the underscore character, that is, -any character which can be part of a Perl "word". The definition of letters and -digits is controlled by PCRE's character tables, and may vary if locale- -specific matching is taking place (see -"Locale support" -in the -pcreapi -page). For example, in the "fr" (French) locale, some character codes greater -than 128 are used for accented letters, and these are matched by \w. -
--These character type sequences can appear both inside and outside character -classes. They each match one character of the appropriate type. If the current -matching point is at the end of the subject string, all of them fail, since -there is no character to match. -
--The fourth use of backslash is for certain simple assertions. An assertion -specifies a condition that has to be met at a particular point in a match, -without consuming any characters from the subject string. The use of -subpatterns for more complicated assertions is described below. The backslashed -assertions are -
--
- \b matches at a word boundary - \B matches when not at a word boundary - \A matches at start of subject - \Z matches at end of subject or before newline at end - \z matches at end of subject - \G matches at first matching position in subject -- -
-These assertions may not appear in character classes (but note that \b has a -different meaning, namely the backspace character, inside a character class). -
--A word boundary is a position in the subject string where the current character -and the previous character do not both match \w or \W (i.e. one matches -\w and the other matches \W), or the start or end of the string if the -first or last character matches \w, respectively. -
--The \A, \Z, and \z assertions differ from the traditional circumflex and -dollar (described below) in that they only ever match at the very start and end -of the subject string, whatever options are set. Thus, they are independent of -multiline mode. -
--They are not affected by the PCRE_NOTBOL or PCRE_NOTEOL options. If the -startoffset argument of pcre_exec() is non-zero, indicating that -matching is to start at a point other than the beginning of the subject, \A -can never match. The difference between \Z and \z is that \Z matches before -a newline that is the last character of the string as well as at the end of the -string, whereas \z matches only at the end. -
--The \G assertion is true only when the current matching position is at the -start point of the match, as specified by the startoffset argument of -pcre_exec(). It differs from \A when the value of startoffset is -non-zero. By calling pcre_exec() multiple times with appropriate -arguments, you can mimic Perl's /g option, and it is in this kind of -implementation where \G can be useful. -
--Note, however, that PCRE's interpretation of \G, as the start of the current -match, is subtly different from Perl's, which defines it as the end of the -previous match. In Perl, these can be different when the previously matched -string was empty. Because PCRE does just one match at a time, it cannot -reproduce this behaviour. -
--If all the alternatives of a pattern begin with \G, the expression is anchored -to the starting match position, and the "anchored" flag is set in the compiled -regular expression. -
--Outside a character class, in the default matching mode, the circumflex -character is an assertion which is true only if the current matching point is -at the start of the subject string. If the startoffset argument of -pcre_exec() is non-zero, circumflex can never match if the PCRE_MULTILINE -option is unset. Inside a character class, circumflex has an entirely different -meaning (see below). -
--Circumflex need not be the first character of the pattern if a number of -alternatives are involved, but it should be the first thing in each alternative -in which it appears if the pattern is ever to match that branch. If all -possible alternatives start with a circumflex, that is, if the pattern is -constrained to match only at the start of the subject, it is said to be an -"anchored" pattern. (There are also other constructs that can cause a pattern -to be anchored.) -
--A dollar character is an assertion which is true only if the current matching -point is at the end of the subject string, or immediately before a newline -character that is the last character in the string (by default). Dollar need -not be the last character of the pattern if a number of alternatives are -involved, but it should be the last item in any branch in which it appears. -Dollar has no special meaning in a character class. -
--The meaning of dollar can be changed so that it matches only at the very end of -the string, by setting the PCRE_DOLLAR_ENDONLY option at compile time. This -does not affect the \Z assertion. -
--The meanings of the circumflex and dollar characters are changed if the -PCRE_MULTILINE option is set. When this is the case, they match immediately -after and immediately before an internal newline character, respectively, in -addition to matching at the start and end of the subject string. For example, -the pattern /^abc$/ matches the subject string "def\nabc" in multiline mode, -but not otherwise. Consequently, patterns that are anchored in single line mode -because all branches start with ^ are not anchored in multiline mode, and a -match for circumflex is possible when the startoffset argument of -pcre_exec() is non-zero. The PCRE_DOLLAR_ENDONLY option is ignored if -PCRE_MULTILINE is set. -
--Note that the sequences \A, \Z, and \z can be used to match the start and -end of the subject in both modes, and if all branches of a pattern start with -\A it is always anchored, whether PCRE_MULTILINE is set or not. -
--Outside a character class, a dot in the pattern matches any one character in -the subject, including a non-printing character, but not (by default) newline. -In UTF-8 mode, a dot matches any UTF-8 character, which might be more than one -byte long, except (by default) for newline. If the PCRE_DOTALL option is set, -dots match newlines as well. The handling of dot is entirely independent of the -handling of circumflex and dollar, the only relationship being that they both -involve newline characters. Dot has no special meaning in a character class. -
--Outside a character class, the escape sequence \C matches any one byte, both -in and out of UTF-8 mode. Unlike a dot, it always matches a newline. The -feature is provided in Perl in order to match individual bytes in UTF-8 mode. -Because it breaks up UTF-8 characters into individual bytes, what remains in -the string may be a malformed UTF-8 string. For this reason it is best avoided. -
--PCRE does not allow \C to appear in lookbehind assertions (see below), because -in UTF-8 mode it makes it impossible to calculate the length of the lookbehind. -
--An opening square bracket introduces a character class, terminated by a closing -square bracket. A closing square bracket on its own is not special. If a -closing square bracket is required as a member of the class, it should be the -first data character in the class (after an initial circumflex, if present) or -escaped with a backslash. -
--A character class matches a single character in the subject. In UTF-8 mode, the -character may occupy more than one byte. A matched character must be in the set -of characters defined by the class, unless the first character in the class -definition is a circumflex, in which case the subject character must not be in -the set defined by the class. If a circumflex is actually required as a member -of the class, ensure it is not the first character, or escape it with a -backslash. -
--For example, the character class [aeiou] matches any lower case vowel, while -[^aeiou] matches any character that is not a lower case vowel. Note that a -circumflex is just a convenient notation for specifying the characters which -are in the class by enumerating those that are not. It is not an assertion: it -still consumes a character from the subject string, and fails if the current -pointer is at the end of the string. -
--In UTF-8 mode, characters with values greater than 255 can be included in a -class as a literal string of bytes, or by using the \x{ escaping mechanism. -
--When caseless matching is set, any letters in a class represent both their -upper case and lower case versions, so for example, a caseless [aeiou] matches -"A" as well as "a", and a caseless [^aeiou] does not match "A", whereas a -caseful version would. PCRE does not support the concept of case for characters -with values greater than 255. -
--The newline character is never treated in any special way in character classes, -whatever the setting of the PCRE_DOTALL or PCRE_MULTILINE options is. A class -such as [^a] will always match a newline. -
--The minus (hyphen) character can be used to specify a range of characters in a -character class. For example, [d-m] matches any letter between d and m, -inclusive. If a minus character is required in a class, it must be escaped with -a backslash or appear in a position where it cannot be interpreted as -indicating a range, typically as the first or last character in the class. -
--It is not possible to have the literal character "]" as the end character of a -range. A pattern such as [W-]46] is interpreted as a class of two characters -("W" and "-") followed by a literal string "46]", so it would match "W46]" or -"-46]". However, if the "]" is escaped with a backslash it is interpreted as -the end of range, so [W-\]46] is interpreted as a single class containing a -range followed by two separate characters. The octal or hexadecimal -representation of "]" can also be used to end a range. -
--Ranges operate in the collating sequence of character values. They can also be -used for characters specified numerically, for example [\000-\037]. In UTF-8 -mode, ranges can include characters whose values are greater than 255, for -example [\x{100}-\x{2ff}]. -
--If a range that includes letters is used when caseless matching is set, it -matches the letters in either case. For example, [W-c] is equivalent to -[][\^_`wxyzabc], matched caselessly, and if character tables for the "fr" -locale are in use, [\xc8-\xcb] matches accented E characters in both cases. -
--The character types \d, \D, \s, \S, \w, and \W may also appear in a -character class, and add the characters that they match to the class. For -example, [\dABCDEF] matches any hexadecimal digit. A circumflex can -conveniently be used with the upper case character types to specify a more -restricted set of characters than the matching lower case type. For example, -the class [^\W_] matches any letter or digit, but not underscore. -
--All non-alphameric characters other than \, -, ^ (at the start) and the -terminating ] are non-special in character classes, but it does no harm if they -are escaped. -
--Perl supports the POSIX notation for character classes, which uses names -enclosed by [: and :] within the enclosing square brackets. PCRE also supports -this notation. For example, -
--
- [01[:alpha:]%] -- -
-matches "0", "1", any alphabetic character, or "%". The supported class names -are -
--
- alnum letters and digits - alpha letters - ascii character codes 0 - 127 - blank space or tab only - cntrl control characters - digit decimal digits (same as \d) - graph printing characters, excluding space - lower lower case letters - print printing characters, including space - punct printing characters, excluding letters and digits - space white space (not quite the same as \s) - upper upper case letters - word "word" characters (same as \w) - xdigit hexadecimal digits -- -
-The "space" characters are HT (9), LF (10), VT (11), FF (12), CR (13), and -space (32). Notice that this list includes the VT character (code 11). This -makes "space" different to \s, which does not include VT (for Perl -compatibility). -
--The name "word" is a Perl extension, and "blank" is a GNU extension from Perl -5.8. Another Perl extension is negation, which is indicated by a ^ character -after the colon. For example, -
--
- [12[:^digit:]] -- -
-matches "1", "2", or any non-digit. PCRE (and Perl) also recognize the POSIX -syntax [.ch.] and [=ch=] where "ch" is a "collating element", but these are not -supported, and an error is given if they are encountered. -
--In UTF-8 mode, characters with values greater than 255 do not match any of -the POSIX character classes. -
--Vertical bar characters are used to separate alternative patterns. For example, -the pattern -
--
- gilbert|sullivan -- -
-matches either "gilbert" or "sullivan". Any number of alternatives may appear, -and an empty alternative is permitted (matching the empty string). -The matching process tries each alternative in turn, from left to right, -and the first one that succeeds is used. If the alternatives are within a -subpattern (defined below), "succeeds" means matching the rest of the main -pattern as well as the alternative in the subpattern. -
--The settings of the PCRE_CASELESS, PCRE_MULTILINE, PCRE_DOTALL, and -PCRE_EXTENDED options can be changed from within the pattern by a sequence of -Perl option letters enclosed between "(?" and ")". The option letters are -
--
- i for PCRE_CASELESS - m for PCRE_MULTILINE - s for PCRE_DOTALL - x for PCRE_EXTENDED -- -
-For example, (?im) sets caseless, multiline matching. It is also possible to -unset these options by preceding the letter with a hyphen, and a combined -setting and unsetting such as (?im-sx), which sets PCRE_CASELESS and -PCRE_MULTILINE while unsetting PCRE_DOTALL and PCRE_EXTENDED, is also -permitted. If a letter appears both before and after the hyphen, the option is -unset. -
--When an option change occurs at top level (that is, not inside subpattern -parentheses), the change applies to the remainder of the pattern that follows. -If the change is placed right at the start of a pattern, PCRE extracts it into -the global options (and it will therefore show up in data extracted by the -pcre_fullinfo() function). -
--An option change within a subpattern affects only that part of the current -pattern that follows it, so -
--
- (a(?i)b)c -- -
-matches abc and aBc and no other strings (assuming PCRE_CASELESS is not used). -By this means, options can be made to have different settings in different -parts of the pattern. Any changes made in one alternative do carry on -into subsequent branches within the same subpattern. For example, -
--
- (a(?i)b|c) -- -
-matches "ab", "aB", "c", and "C", even though when matching "C" the first -branch is abandoned before the option setting. This is because the effects of -option settings happen at compile time. There would be some very weird -behaviour otherwise. -
--The PCRE-specific options PCRE_UNGREEDY and PCRE_EXTRA can be changed in the -same way as the Perl-compatible options by using the characters U and X -respectively. The (?X) flag setting is special in that it must always occur -earlier in the pattern than any of the additional features it turns on, even -when it is at top level. It is best put at the start. -
--Subpatterns are delimited by parentheses (round brackets), which can be nested. -Marking part of a pattern as a subpattern does two things: -
--1. It localizes a set of alternatives. For example, the pattern -
--
- cat(aract|erpillar|) -- -
-matches one of the words "cat", "cataract", or "caterpillar". Without the -parentheses, it would match "cataract", "erpillar" or the empty string. -
--2. It sets up the subpattern as a capturing subpattern (as defined above). -When the whole pattern matches, that portion of the subject string that matched -the subpattern is passed back to the caller via the ovector argument of -pcre_exec(). Opening parentheses are counted from left to right (starting -from 1) to obtain the numbers of the capturing subpatterns. -
--For example, if the string "the red king" is matched against the pattern -
--
- the ((red|white) (king|queen)) -- -
-the captured substrings are "red king", "red", and "king", and are numbered 1, -2, and 3, respectively. -
--The fact that plain parentheses fulfil two functions is not always helpful. -There are often times when a grouping subpattern is required without a -capturing requirement. If an opening parenthesis is followed by a question mark -and a colon, the subpattern does not do any capturing, and is not counted when -computing the number of any subsequent capturing subpatterns. For example, if -the string "the white queen" is matched against the pattern -
--
- the ((?:red|white) (king|queen)) -- -
-the captured substrings are "white queen" and "queen", and are numbered 1 and -2. The maximum number of capturing subpatterns is 65535, and the maximum depth -of nesting of all subpatterns, both capturing and non-capturing, is 200. -
--As a convenient shorthand, if any option settings are required at the start of -a non-capturing subpattern, the option letters may appear between the "?" and -the ":". Thus the two patterns -
--
- (?i:saturday|sunday) - (?:(?i)saturday|sunday) -- -
-match exactly the same set of strings. Because alternative branches are tried -from left to right, and options are not reset until the end of the subpattern -is reached, an option setting in one branch does affect subsequent branches, so -the above patterns match "SUNDAY" as well as "Saturday". -
--Identifying capturing parentheses by number is simple, but it can be very hard -to keep track of the numbers in complicated regular expressions. Furthermore, -if an expression is modified, the numbers may change. To help with the -difficulty, PCRE supports the naming of subpatterns, something that Perl does -not provide. The Python syntax (?P<name>...) is used. Names consist of -alphanumeric characters and underscores, and must be unique within a pattern. -
--Named capturing parentheses are still allocated numbers as well as names. The -PCRE API provides function calls for extracting the name-to-number translation -table from a compiled pattern. For further details see the -pcreapi -documentation. -
--Repetition is specified by quantifiers, which can follow any of the following -items: -
--
- a literal data character - the . metacharacter - the \C escape sequence - escapes such as \d that match single characters - a character class - a back reference (see next section) - a parenthesized subpattern (unless it is an assertion) -- -
-The general repetition quantifier specifies a minimum and maximum number of -permitted matches, by giving the two numbers in curly brackets (braces), -separated by a comma. The numbers must be less than 65536, and the first must -be less than or equal to the second. For example: -
--
- z{2,4} -- -
-matches "zz", "zzz", or "zzzz". A closing brace on its own is not a special -character. If the second number is omitted, but the comma is present, there is -no upper limit; if the second number and the comma are both omitted, the -quantifier specifies an exact number of required matches. Thus -
--
- [aeiou]{3,} -- -
-matches at least 3 successive vowels, but may match many more, while -
--
- \d{8} -- -
-matches exactly 8 digits. An opening curly bracket that appears in a position -where a quantifier is not allowed, or one that does not match the syntax of a -quantifier, is taken as a literal character. For example, {,6} is not a -quantifier, but a literal string of four characters. -
--In UTF-8 mode, quantifiers apply to UTF-8 characters rather than to individual -bytes. Thus, for example, \x{100}{2} matches two UTF-8 characters, each of -which is represented by a two-byte sequence. -
--The quantifier {0} is permitted, causing the expression to behave as if the -previous item and the quantifier were not present. -
--For convenience (and historical compatibility) the three most common -quantifiers have single-character abbreviations: -
--
- * is equivalent to {0,} - + is equivalent to {1,} - ? is equivalent to {0,1} -- -
-It is possible to construct infinite loops by following a subpattern that can -match no characters with a quantifier that has no upper limit, for example: -
--
- (a?)* -- -
-Earlier versions of Perl and PCRE used to give an error at compile time for -such patterns. However, because there are cases where this can be useful, such -patterns are now accepted, but if any repetition of the subpattern does in fact -match no characters, the loop is forcibly broken. -
--By default, the quantifiers are "greedy", that is, they match as much as -possible (up to the maximum number of permitted times), without causing the -rest of the pattern to fail. The classic example of where this gives problems -is in trying to match comments in C programs. These appear between the -sequences /* and */ and within the sequence, individual * and / characters may -appear. An attempt to match C comments by applying the pattern -
--
- /\*.*\*/ -- -
-to the string -
--
- /* first command */ not comment /* second comment */ -- -
-fails, because it matches the entire string owing to the greediness of the .* -item. -
--However, if a quantifier is followed by a question mark, it ceases to be -greedy, and instead matches the minimum number of times possible, so the -pattern -
--
- /\*.*?\*/ -- -
-does the right thing with the C comments. The meaning of the various -quantifiers is not otherwise changed, just the preferred number of matches. -Do not confuse this use of question mark with its use as a quantifier in its -own right. Because it has two uses, it can sometimes appear doubled, as in -
--
- \d??\d -- -
-which matches one digit by preference, but can match two if that is the only -way the rest of the pattern matches. -
--If the PCRE_UNGREEDY option is set (an option which is not available in Perl), -the quantifiers are not greedy by default, but individual ones can be made -greedy by following them with a question mark. In other words, it inverts the -default behaviour. -
--When a parenthesized subpattern is quantified with a minimum repeat count that -is greater than 1 or with a limited maximum, more store is required for the -compiled pattern, in proportion to the size of the minimum or maximum. -
--If a pattern starts with .* or .{0,} and the PCRE_DOTALL option (equivalent -to Perl's /s) is set, thus allowing the . to match newlines, the pattern is -implicitly anchored, because whatever follows will be tried against every -character position in the subject string, so there is no point in retrying the -overall match at any position after the first. PCRE normally treats such a -pattern as though it were preceded by \A. -
--In cases where it is known that the subject string contains no newlines, it is -worth setting PCRE_DOTALL in order to obtain this optimization, or -alternatively using ^ to indicate anchoring explicitly. -
--However, there is one situation where the optimization cannot be used. When .* -is inside capturing parentheses that are the subject of a backreference -elsewhere in the pattern, a match at the start may fail, and a later one -succeed. Consider, for example: -
--
- (.*)abc\1 -- -
-If the subject is "xyz123abc123" the match point is the fourth character. For -this reason, such a pattern is not implicitly anchored. -
--When a capturing subpattern is repeated, the value captured is the substring -that matched the final iteration. For example, after -
--
- (tweedle[dume]{3}\s*)+ -- -
-has matched "tweedledum tweedledee" the value of the captured substring is -"tweedledee". However, if there are nested capturing subpatterns, the -corresponding captured values may have been set in previous iterations. For -example, after -
--
- /(a|(b))+/ -- -
-matches "aba" the value of the second captured substring is "b". -
--With both maximizing and minimizing repetition, failure of what follows -normally causes the repeated item to be re-evaluated to see if a different -number of repeats allows the rest of the pattern to match. Sometimes it is -useful to prevent this, either to change the nature of the match, or to cause -it fail earlier than it otherwise might, when the author of the pattern knows -there is no point in carrying on. -
--Consider, for example, the pattern \d+foo when applied to the subject line -
--
- 123456bar -- -
-After matching all 6 digits and then failing to match "foo", the normal -action of the matcher is to try again with only 5 digits matching the \d+ -item, and then with 4, and so on, before ultimately failing. "Atomic grouping" -(a term taken from Jeffrey Friedl's book) provides the means for specifying -that once a subpattern has matched, it is not to be re-evaluated in this way. -
--If we use atomic grouping for the previous example, the matcher would give up -immediately on failing to match "foo" the first time. The notation is a kind of -special parenthesis, starting with (?> as in this example: -
--
- (?>\d+)foo -- -
-This kind of parenthesis "locks up" the part of the pattern it contains once -it has matched, and a failure further into the pattern is prevented from -backtracking into it. Backtracking past it to previous items, however, works as -normal. -
--An alternative description is that a subpattern of this type matches the string -of characters that an identical standalone pattern would match, if anchored at -the current point in the subject string. -
--Atomic grouping subpatterns are not capturing subpatterns. Simple cases such as -the above example can be thought of as a maximizing repeat that must swallow -everything it can. So, while both \d+ and \d+? are prepared to adjust the -number of digits they match in order to make the rest of the pattern match, -(?>\d+) can only match an entire sequence of digits. -
--Atomic groups in general can of course contain arbitrarily complicated -subpatterns, and can be nested. However, when the subpattern for an atomic -group is just a single repeated item, as in the example above, a simpler -notation, called a "possessive quantifier" can be used. This consists of an -additional + character following a quantifier. Using this notation, the -previous example can be rewritten as -
--
- \d++bar -- -
-Possessive quantifiers are always greedy; the setting of the PCRE_UNGREEDY -option is ignored. They are a convenient notation for the simpler forms of -atomic group. However, there is no difference in the meaning or processing of a -possessive quantifier and the equivalent atomic group. -
--The possessive quantifier syntax is an extension to the Perl syntax. It -originates in Sun's Java package. -
--When a pattern contains an unlimited repeat inside a subpattern that can itself -be repeated an unlimited number of times, the use of an atomic group is the -only way to avoid some failing matches taking a very long time indeed. The -pattern -
--
- (\D+|<\d+>)*[!?] -- -
-matches an unlimited number of substrings that either consist of non-digits, or -digits enclosed in <>, followed by either ! or ?. When it matches, it runs -quickly. However, if it is applied to -
--
- aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa -- -
-it takes a long time before reporting failure. This is because the string can -be divided between the two repeats in a large number of ways, and all have to -be tried. (The example used [!?] rather than a single character at the end, -because both PCRE and Perl have an optimization that allows for fast failure -when a single character is used. They remember the last single character that -is required for a match, and fail early if it is not present in the string.) -If the pattern is changed to -
--
- ((?>\D+)|<\d+>)*[!?] -- -
-sequences of non-digits cannot be broken, and failure happens quickly. -
--Outside a character class, a backslash followed by a digit greater than 0 (and -possibly further digits) is a back reference to a capturing subpattern earlier -(that is, to its left) in the pattern, provided there have been that many -previous capturing left parentheses. -
--However, if the decimal number following the backslash is less than 10, it is -always taken as a back reference, and causes an error only if there are not -that many capturing left parentheses in the entire pattern. In other words, the -parentheses that are referenced need not be to the left of the reference for -numbers less than 10. See the section entitled "Backslash" above for further -details of the handling of digits following a backslash. -
--A back reference matches whatever actually matched the capturing subpattern in -the current subject string, rather than anything matching the subpattern -itself (see -"Subpatterns as subroutines" -below for a way of doing that). So the pattern -
--
- (sens|respons)e and \1ibility -- -
-matches "sense and sensibility" and "response and responsibility", but not -"sense and responsibility". If caseful matching is in force at the time of the -back reference, the case of letters is relevant. For example, -
--
- ((?i)rah)\s+\1 -- -
-matches "rah rah" and "RAH RAH", but not "RAH rah", even though the original -capturing subpattern is matched caselessly. -
--Back references to named subpatterns use the Python syntax (?P=name). We could -rewrite the above example as follows: -
--
- (?<p1>(?i)rah)\s+(?P=p1) -- -
-There may be more than one back reference to the same subpattern. If a -subpattern has not actually been used in a particular match, any back -references to it always fail. For example, the pattern -
--
- (a|(bc))\2 -- -
-always fails if it starts to match "a" rather than "bc". Because there may be -many capturing parentheses in a pattern, all digits following the backslash are -taken as part of a potential back reference number. If the pattern continues -with a digit character, some delimiter must be used to terminate the back -reference. If the PCRE_EXTENDED option is set, this can be whitespace. -Otherwise an empty comment can be used. -
--A back reference that occurs inside the parentheses to which it refers fails -when the subpattern is first used, so, for example, (a\1) never matches. -However, such references can be useful inside repeated subpatterns. For -example, the pattern -
--
- (a|b\1)+ -- -
-matches any number of "a"s and also "aba", "ababbaa" etc. At each iteration of -the subpattern, the back reference matches the character string corresponding -to the previous iteration. In order for this to work, the pattern must be such -that the first iteration does not need to match the back reference. This can be -done using alternation, as in the example above, or by a quantifier with a -minimum of zero. -
--An assertion is a test on the characters following or preceding the current -matching point that does not actually consume any characters. The simple -assertions coded as \b, \B, \A, \G, \Z, \z, ^ and $ are described above. -More complicated assertions are coded as subpatterns. There are two kinds: -those that look ahead of the current position in the subject string, and those -that look behind it. -
--An assertion subpattern is matched in the normal way, except that it does not -cause the current matching position to be changed. Lookahead assertions start -with (?= for positive assertions and (?! for negative assertions. For example, -
--
- \w+(?=;) -- -
-matches a word followed by a semicolon, but does not include the semicolon in -the match, and -
--
- foo(?!bar) -- -
-matches any occurrence of "foo" that is not followed by "bar". Note that the -apparently similar pattern -
--
- (?!foo)bar -- -
-does not find an occurrence of "bar" that is preceded by something other than -"foo"; it finds any occurrence of "bar" whatsoever, because the assertion -(?!foo) is always true when the next three characters are "bar". A -lookbehind assertion is needed to achieve this effect. -
--If you want to force a matching failure at some point in a pattern, the most -convenient way to do it is with (?!) because an empty string always matches, so -an assertion that requires there not to be an empty string must always fail. -
--Lookbehind assertions start with (?<= for positive assertions and (?<! for -negative assertions. For example, -
--
- (?<!foo)bar -- -
-does find an occurrence of "bar" that is not preceded by "foo". The contents of -a lookbehind assertion are restricted such that all the strings it matches must -have a fixed length. However, if there are several alternatives, they do not -all have to have the same fixed length. Thus -
--
- (?<=bullock|donkey) -- -
-is permitted, but -
--
- (?<!dogs?|cats?) -- -
-causes an error at compile time. Branches that match different length strings -are permitted only at the top level of a lookbehind assertion. This is an -extension compared with Perl (at least for 5.8), which requires all branches to -match the same length of string. An assertion such as -
--
- (?<=ab(c|de)) -- -
-is not permitted, because its single top-level branch can match two different -lengths, but it is acceptable if rewritten to use two top-level branches: -
--
- (?<=abc|abde) -- -
-The implementation of lookbehind assertions is, for each alternative, to -temporarily move the current position back by the fixed width and then try to -match. If there are insufficient characters before the current position, the -match is deemed to fail. -
--PCRE does not allow the \C escape (which matches a single byte in UTF-8 mode) -to appear in lookbehind assertions, because it makes it impossible to calculate -the length of the lookbehind. -
--Atomic groups can be used in conjunction with lookbehind assertions to specify -efficient matching at the end of the subject string. Consider a simple pattern -such as -
--
- abcd$ -- -
-when applied to a long string that does not match. Because matching proceeds -from left to right, PCRE will look for each "a" in the subject and then see if -what follows matches the rest of the pattern. If the pattern is specified as -
--
- ^.*abcd$ -- -
-the initial .* matches the entire string at first, but when this fails (because -there is no following "a"), it backtracks to match all but the last character, -then all but the last two characters, and so on. Once again the search for "a" -covers the entire string, from right to left, so we are no better off. However, -if the pattern is written as -
--
- ^(?>.*)(?<=abcd) -- -
-or, equivalently, -
--
- ^.*+(?<=abcd) -- -
-there can be no backtracking for the .* item; it can match only the entire -string. The subsequent lookbehind assertion does a single test on the last four -characters. If it fails, the match fails immediately. For long strings, this -approach makes a significant difference to the processing time. -
--Several assertions (of any sort) may occur in succession. For example, -
--
- (?<=\d{3})(?<!999)foo -- -
-matches "foo" preceded by three digits that are not "999". Notice that each of -the assertions is applied independently at the same point in the subject -string. First there is a check that the previous three characters are all -digits, and then there is a check that the same three characters are not "999". -This pattern does not match "foo" preceded by six characters, the first -of which are digits and the last three of which are not "999". For example, it -doesn't match "123abcfoo". A pattern to do that is -
--
- (?<=\d{3}...)(?<!999)foo -- -
-This time the first assertion looks at the preceding six characters, checking -that the first three are digits, and then the second assertion checks that the -preceding three characters are not "999". -
--Assertions can be nested in any combination. For example, -
--
- (?<=(?<!foo)bar)baz -- -
-matches an occurrence of "baz" that is preceded by "bar" which in turn is not -preceded by "foo", while -
--
- (?<=\d{3}(?!999)...)foo -- -
-is another pattern which matches "foo" preceded by three digits and any three -characters that are not "999". -
--Assertion subpatterns are not capturing subpatterns, and may not be repeated, -because it makes no sense to assert the same thing several times. If any kind -of assertion contains capturing subpatterns within it, these are counted for -the purposes of numbering the capturing subpatterns in the whole pattern. -However, substring capturing is carried out only for positive assertions, -because it does not make sense for negative assertions. -
--It is possible to cause the matching process to obey a subpattern -conditionally or to choose between two alternative subpatterns, depending on -the result of an assertion, or whether a previous capturing subpattern matched -or not. The two possible forms of conditional subpattern are -
--
- (?(condition)yes-pattern) - (?(condition)yes-pattern|no-pattern) -- -
-If the condition is satisfied, the yes-pattern is used; otherwise the -no-pattern (if present) is used. If there are more than two alternatives in the -subpattern, a compile-time error occurs. -
--There are three kinds of condition. If the text between the parentheses -consists of a sequence of digits, the condition is satisfied if the capturing -subpattern of that number has previously matched. The number must be greater -than zero. Consider the following pattern, which contains non-significant white -space to make it more readable (assume the PCRE_EXTENDED option) and to divide -it into three parts for ease of discussion: -
--
- ( \( )? [^()]+ (?(1) \) ) -- -
-The first part matches an optional opening parenthesis, and if that -character is present, sets it as the first captured substring. The second part -matches one or more characters that are not parentheses. The third part is a -conditional subpattern that tests whether the first set of parentheses matched -or not. If they did, that is, if subject started with an opening parenthesis, -the condition is true, and so the yes-pattern is executed and a closing -parenthesis is required. Otherwise, since no-pattern is not present, the -subpattern matches nothing. In other words, this pattern matches a sequence of -non-parentheses, optionally enclosed in parentheses. -
--If the condition is the string (R), it is satisfied if a recursive call to the -pattern or subpattern has been made. At "top level", the condition is false. -This is a PCRE extension. Recursive patterns are described in the next section. -
--If the condition is not a sequence of digits or (R), it must be an assertion. -This may be a positive or negative lookahead or lookbehind assertion. Consider -this pattern, again containing non-significant white space, and with the two -alternatives on the second line: -
--
- (?(?=[^a-z]*[a-z]) - \d{2}-[a-z]{3}-\d{2} | \d{2}-\d{2}-\d{2} ) -- -
-The condition is a positive lookahead assertion that matches an optional -sequence of non-letters followed by a letter. In other words, it tests for the -presence of at least one letter in the subject. If a letter is found, the -subject is matched against the first alternative; otherwise it is matched -against the second. This pattern matches strings in one of the two forms -dd-aaa-dd or dd-dd-dd, where aaa are letters and dd are digits. -
--The sequence (?# marks the start of a comment which continues up to the next -closing parenthesis. Nested parentheses are not permitted. The characters -that make up a comment play no part in the pattern matching at all. -
--If the PCRE_EXTENDED option is set, an unescaped # character outside a -character class introduces a comment that continues up to the next newline -character in the pattern. -
--Consider the problem of matching a string in parentheses, allowing for -unlimited nested parentheses. Without the use of recursion, the best that can -be done is to use a pattern that matches up to some fixed depth of nesting. It -is not possible to handle an arbitrary nesting depth. Perl has provided an -experimental facility that allows regular expressions to recurse (amongst other -things). It does this by interpolating Perl code in the expression at run time, -and the code can refer to the expression itself. A Perl pattern to solve the -parentheses problem can be created like this: -
--
- $re = qr{\( (?: (?>[^()]+) | (?p{$re}) )* \)}x; -- -
-The (?p{...}) item interpolates Perl code at run time, and in this case refers -recursively to the pattern in which it appears. Obviously, PCRE cannot support -the interpolation of Perl code. Instead, it supports some special syntax for -recursion of the entire pattern, and also for individual subpattern recursion. -
--The special item that consists of (? followed by a number greater than zero and -a closing parenthesis is a recursive call of the subpattern of the given -number, provided that it occurs inside that subpattern. (If not, it is a -"subroutine" call, which is described in the next section.) The special item -(?R) is a recursive call of the entire regular expression. -
--For example, this PCRE pattern solves the nested parentheses problem (assume -the PCRE_EXTENDED option is set so that white space is ignored): -
--
- \( ( (?>[^()]+) | (?R) )* \) -- -
-First it matches an opening parenthesis. Then it matches any number of -substrings which can either be a sequence of non-parentheses, or a recursive -match of the pattern itself (that is a correctly parenthesized substring). -Finally there is a closing parenthesis. -
--If this were part of a larger pattern, you would not want to recurse the entire -pattern, so instead you could use this: -
--
- ( \( ( (?>[^()]+) | (?1) )* \) ) -- -
-We have put the pattern into parentheses, and caused the recursion to refer to -them instead of the whole pattern. In a larger pattern, keeping track of -parenthesis numbers can be tricky. It may be more convenient to use named -parentheses instead. For this, PCRE uses (?P>name), which is an extension to -the Python syntax that PCRE uses for named parentheses (Perl does not provide -named parentheses). We could rewrite the above example as follows: -
--
- (?P<pn> \( ( (?>[^()]+) | (?P>pn) )* \) ) -- -
-This particular example pattern contains nested unlimited repeats, and so the -use of atomic grouping for matching strings of non-parentheses is important -when applying the pattern to strings that do not match. For example, when this -pattern is applied to -
--
- (aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa() -- -
-it yields "no match" quickly. However, if atomic grouping is not used, -the match runs for a very long time indeed because there are so many different -ways the + and * repeats can carve up the subject, and all have to be tested -before failure can be reported. -
--At the end of a match, the values set for any capturing subpatterns are those -from the outermost level of the recursion at which the subpattern value is set. -If you want to obtain intermediate values, a callout function can be used (see -below and the -pcrecallout -documentation). If the pattern above is matched against -
--
- (ab(cd)ef) -- -
-the value for the capturing parentheses is "ef", which is the last value taken -on at the top level. If additional parentheses are added, giving -
--
- \( ( ( (?>[^()]+) | (?R) )* ) \) - ^ ^ - ^ ^ -- -
-the string they capture is "ab(cd)ef", the contents of the top level -parentheses. If there are more than 15 capturing parentheses in a pattern, PCRE -has to obtain extra memory to store data during a recursion, which it does by -using pcre_malloc, freeing it via pcre_free afterwards. If no -memory can be obtained, the match fails with the PCRE_ERROR_NOMEMORY error. -
--Do not confuse the (?R) item with the condition (R), which tests for recursion. -Consider this pattern, which matches text in angle brackets, allowing for -arbitrary nesting. Only digits are allowed in nested brackets (that is, when -recursing), whereas any characters are permitted at the outer level. -
--
- < (?: (?(R) \d++ | [^<>]*+) | (?R)) * > -- -
-In this pattern, (?(R) is the start of a conditional subpattern, with two -different alternatives for the recursive and non-recursive cases. The (?R) item -is the actual recursive call. -
--If the syntax for a recursive subpattern reference (either by number or by -name) is used outside the parentheses to which it refers, it operates like a -subroutine in a programming language. An earlier example pointed out that the -pattern -
--
- (sens|respons)e and \1ibility -- -
-matches "sense and sensibility" and "response and responsibility", but not -"sense and responsibility". If instead the pattern -
--
- (sens|respons)e and (?1)ibility -- -
-is used, it does match "sense and responsibility" as well as the other two -strings. Such references must, however, follow the subpattern to which they -refer. -
--Perl has a feature whereby using the sequence (?{...}) causes arbitrary Perl -code to be obeyed in the middle of matching a regular expression. This makes it -possible, amongst other things, to extract different substrings that match the -same pair of parentheses when there is a repetition. -
--PCRE provides a similar feature, but of course it cannot obey arbitrary Perl -code. The feature is called "callout". The caller of PCRE provides an external -function by putting its entry point in the global variable pcre_callout. -By default, this variable contains NULL, which disables all calling out. -
--Within a regular expression, (?C) indicates the points at which the external -function is to be called. If you want to identify different callout points, you -can put a number less than 256 after the letter C. The default value is zero. -For example, this pattern has two callout points: -
--
- (?C1)\dabc(?C2)def -- -
-During matching, when PCRE reaches a callout point (and pcre_callout is -set), the external function is called. It is provided with the number of the -callout, and, optionally, one item of data originally supplied by the caller of -pcre_exec(). The callout function may cause matching to backtrack, or to -fail altogether. A complete description of the interface to the callout -function is given in the -pcrecallout -documentation. -
-
-Last updated: 03 February 2003
-
-Copyright © 1997-2003 University of Cambridge.
diff --git a/external-libs/pcre/doc/html/pcreperform.html b/external-libs/pcre/doc/html/pcreperform.html
deleted file mode 100644
index 418ac6d4..00000000
--- a/external-libs/pcre/doc/html/pcreperform.html
+++ /dev/null
@@ -1,93 +0,0 @@
-
-
-Certain items that may appear in regular expression patterns are more efficient -than others. It is more efficient to use a character class like [aeiou] than a -set of alternatives such as (a|e|i|o|u). In general, the simplest construction -that provides the required behaviour is usually the most efficient. Jeffrey -Friedl's book contains a lot of discussion about optimizing regular expressions -for efficient performance. -
--When a pattern begins with .* not in parentheses, or in parentheses that are -not the subject of a backreference, and the PCRE_DOTALL option is set, the -pattern is implicitly anchored by PCRE, since it can match only at the start of -a subject string. However, if PCRE_DOTALL is not set, PCRE cannot make this -optimization, because the . metacharacter does not then match a newline, and if -the subject string contains newlines, the pattern may match from the character -immediately following one of them instead of from the very start. For example, -the pattern -
--
- .*second -- -
-matches the subject "first\nand second" (where \n stands for a newline -character), with the match starting at the seventh character. In order to do -this, PCRE has to retry the match starting after every newline in the subject. -
--If you are using such a pattern with subject strings that do not contain -newlines, the best performance is obtained by setting PCRE_DOTALL, or starting -the pattern with ^.* to indicate explicit anchoring. That saves PCRE from -having to scan along the subject looking for a newline to restart at. -
--Beware of patterns that contain nested indefinite repeats. These can take a -long time to run when applied to a string that does not match. Consider the -pattern fragment -
--
- (a+)* -- -
-This can match "aaaa" in 33 different ways, and this number increases very -rapidly as the string gets longer. (The * repeat can match 0, 1, 2, 3, or 4 -times, and for each of those cases other than 0, the + repeats can match -different numbers of times.) When the remainder of the pattern is such that the -entire match is going to fail, PCRE has in principle to try every possible -variation, and this can take an extremely long time. -
--An optimization catches some of the more simple cases such as -
--
- (a+)*b -- -
-where a literal character follows. Before embarking on the standard matching -procedure, PCRE checks that there is a "b" later in the subject string, and if -there is not, it fails the match immediately. However, when there is no -following literal this optimization cannot be used. You can see the difference -by comparing the behaviour of -
--
- (a+)*\d -- -
-with the pattern above. The former gives a failure almost instantly when -applied to a whole line of "a" characters, whereas the latter takes an -appreciable time with strings longer than about 20 characters. -
-
-Last updated: 03 February 2003
-
-Copyright © 1997-2003 University of Cambridge.
diff --git a/external-libs/pcre/doc/html/pcreposix.html b/external-libs/pcre/doc/html/pcreposix.html
deleted file mode 100644
index d0a5e127..00000000
--- a/external-libs/pcre/doc/html/pcreposix.html
+++ /dev/null
@@ -1,237 +0,0 @@
-
-
-#include <pcreposix.h> -
--int regcomp(regex_t *preg, const char *pattern, -int cflags); -
--int regexec(regex_t *preg, const char *string, -size_t nmatch, regmatch_t pmatch[], int eflags); -
--size_t regerror(int errcode, const regex_t *preg, -char *errbuf, size_t errbuf_size); -
--void regfree(regex_t *preg); -
--This set of functions provides a POSIX-style API to the PCRE regular expression -package. See the -pcreapi -documentation for a description of the native API, which contains additional -functionality. -
--The functions described here are just wrapper functions that ultimately call -the PCRE native API. Their prototypes are defined in the pcreposix.h -header file, and on Unix systems the library itself is called -pcreposix.a, so can be accessed by adding -lpcreposix to the -command for linking an application which uses them. Because the POSIX functions -call the native ones, it is also necessary to add \fR-lpcre\fR. -
--I have implemented only those option bits that can be reasonably mapped to PCRE -native options. In addition, the options REG_EXTENDED and REG_NOSUB are defined -with the value zero. They have no effect, but since programs that are written -to the POSIX interface often use them, this makes it easier to slot in PCRE as -a replacement library. Other POSIX options are not even defined. -
--When PCRE is called via these functions, it is only the API that is POSIX-like -in style. The syntax and semantics of the regular expressions themselves are -still those of Perl, subject to the setting of various PCRE options, as -described below. "POSIX-like in style" means that the API approximates to the -POSIX definition; it is not fully POSIX-compatible, and in multi-byte encoding -domains it is probably even less compatible. -
--The header for these functions is supplied as pcreposix.h to avoid any -potential clash with other POSIX libraries. It can, of course, be renamed or -aliased as regex.h, which is the "correct" name. It provides two -structure types, regex_t for compiled internal forms, and -regmatch_t for returning captured substrings. It also defines some -constants whose names start with "REG_"; these are used for setting options and -identifying error codes. -
--The function regcomp() is called to compile a pattern into an -internal form. The pattern is a C string terminated by a binary zero, and -is passed in the argument pattern. The preg argument is a pointer -to a regex_t structure which is used as a base for storing information about -the compiled expression. -
--The argument cflags is either zero, or contains one or more of the bits -defined by the following macros: -
--
- REG_ICASE -- -
-The PCRE_CASELESS option is set when the expression is passed for compilation -to the native function. -
--
- REG_NEWLINE -- -
-The PCRE_MULTILINE option is set when the expression is passed for compilation -to the native function. Note that this does not mimic the defined POSIX -behaviour for REG_NEWLINE (see the following section). -
--In the absence of these flags, no options are passed to the native function. -This means the the regex is compiled with PCRE default semantics. In -particular, the way it handles newline characters in the subject string is the -Perl way, not the POSIX way. Note that setting PCRE_MULTILINE has only -some of the effects specified for REG_NEWLINE. It does not affect the way -newlines are matched by . (they aren't) or by a negative class such as [^a] -(they are). -
--The yield of regcomp() is zero on success, and non-zero otherwise. The -preg structure is filled in on success, and one member of the structure -is public: re_nsub contains the number of capturing subpatterns in -the regular expression. Various error codes are defined in the header file. -
--This area is not simple, because POSIX and Perl take different views of things. -It is not possible to get PCRE to obey POSIX semantics, but then PCRE was never -intended to be a POSIX engine. The following table lists the different -possibilities for matching newline characters in PCRE: -
--
- Default Change with -- -
-
- . matches newline no PCRE_DOTALL - newline matches [^a] yes not changeable - $ matches \n at end yes PCRE_DOLLARENDONLY - $ matches \n in middle no PCRE_MULTILINE - ^ matches \n in middle no PCRE_MULTILINE -- -
-This is the equivalent table for POSIX: -
--
- Default Change with -- -
-
- . matches newline yes REG_NEWLINE - newline matches [^a] yes REG_NEWLINE - $ matches \n at end no REG_NEWLINE - $ matches \n in middle no REG_NEWLINE - ^ matches \n in middle no REG_NEWLINE -- -
-PCRE's behaviour is the same as Perl's, except that there is no equivalent for -PCRE_DOLLARENDONLY in Perl. In both PCRE and Perl, there is no way to stop -newline from matching [^a]. -
--The default POSIX newline handling can be obtained by setting PCRE_DOTALL and -PCRE_DOLLARENDONLY, but there is no way to make PCRE behave exactly as for the -REG_NEWLINE action. -
--The function regexec() is called to match a pre-compiled pattern -preg against a given string, which is terminated by a zero byte, -subject to the options in eflags. These can be: -
--
- REG_NOTBOL -- -
-The PCRE_NOTBOL option is set when calling the underlying PCRE matching -function. -
--
- REG_NOTEOL -- -
-The PCRE_NOTEOL option is set when calling the underlying PCRE matching -function. -
--The portion of the string that was matched, and also any captured substrings, -are returned via the pmatch argument, which points to an array of -nmatch structures of type regmatch_t, containing the members -rm_so and rm_eo. These contain the offset to the first character of -each substring and the offset to the first character after the end of each -substring, respectively. The 0th element of the vector relates to the entire -portion of string that was matched; subsequent elements relate to the -capturing subpatterns of the regular expression. Unused entries in the array -have both structure members set to -1. -
--A successful match yields a zero return; various error codes are defined in the -header file, of which REG_NOMATCH is the "expected" failure code. -
--The regerror() function maps a non-zero errorcode from either -regcomp() or regexec() to a printable message. If preg is not -NULL, the error should have arisen from the use of that structure. A message -terminated by a binary zero is placed in errbuf. The length of the -message, including the zero, is limited to errbuf_size. The yield of the -function is the size of buffer needed to hold the whole message. -
--Compiling a regular expression causes memory to be allocated and associated -with the preg structure. The function regfree() frees all such -memory, after which preg may no longer be used as a compiled expression. -
-
-Philip Hazel <ph10@cam.ac.uk>
-
-University Computing Service,
-
-Cambridge CB2 3QG, England.
-
-Last updated: 03 February 2003
-
-Copyright © 1997-2003 University of Cambridge.
diff --git a/external-libs/pcre/doc/html/pcresample.html b/external-libs/pcre/doc/html/pcresample.html
deleted file mode 100644
index fed41f62..00000000
--- a/external-libs/pcre/doc/html/pcresample.html
+++ /dev/null
@@ -1,79 +0,0 @@
-
-
-A simple, complete demonstration program, to get you started with using PCRE, -is supplied in the file pcredemo.c in the PCRE distribution. -
--The program compiles the regular expression that is its first argument, and -matches it against the subject string in its second argument. No PCRE options -are set, and default character tables are used. If matching succeeds, the -program outputs the portion of the subject that matched, together with the -contents of any captured substrings. -
--If the -g option is given on the command line, the program then goes on to -check for further matches of the same regular expression in the same subject -string. The logic is a little bit tricky because of the possibility of matching -an empty string. Comments in the code explain what is going on. -
--On a Unix system that has PCRE installed in /usr/local, you can compile -the demonstration program using a command like this: -
--
- gcc -o pcredemo pcredemo.c -I/usr/local/include \ - -L/usr/local/lib -lpcre -- -
-Then you can run simple tests like this: -
--
- ./pcredemo 'cat|dog' 'the cat sat on the mat' - ./pcredemo -g 'cat|dog' 'the dog sat on the cat' -- -
-Note that there is a much more comprehensive test program, called -pcretest, which supports many more facilities for testing regular -expressions and the PCRE library. The pcredemo program is provided as a -simple coding example. -
--On some operating systems (e.g. Solaris) you may get an error like this when -you try to run pcredemo: -
--
- ld.so.1: a.out: fatal: libpcre.so.0: open failed: No such file or directory -- -
-This is caused by the way shared library support works on those systems. You -need to add -
--
- -R/usr/local/lib -- -
-to the compile command to get round this problem. -
-
-Last updated: 28 January 2003
-
-Copyright © 1997-2003 University of Cambridge.
diff --git a/external-libs/pcre/doc/html/pcretest.html b/external-libs/pcre/doc/html/pcretest.html
deleted file mode 100644
index 2ba9893d..00000000
--- a/external-libs/pcre/doc/html/pcretest.html
+++ /dev/null
@@ -1,443 +0,0 @@
-
-
-pcretest [-d] [-i] [-m] [-o osize] [-p] [-t] [source] [destination] -
--pcretest was written as a test program for the PCRE regular expression -library itself, but it can also be used for experimenting with regular -expressions. This document describes the features of the test program; for -details of the regular expressions themselves, see the -pcrepattern -documentation. For details of PCRE and its options, see the -pcreapi -documentation. -
---C -Output the version number of the PCRE library, and all available information -about the optional features that are included, and then exit. -
---d -Behave as if each regex had the /D modifier (see below); the internal -form is output after compilation. -
---i -Behave as if each regex had the /I modifier; information about the -compiled pattern is given after compilation. -
---m -Output the size of each compiled pattern after it has been compiled. This is -equivalent to adding /M to each regular expression. For compatibility with -earlier versions of pcretest, -s is a synonym for -m. -
---o osize -Set the number of elements in the output vector that is used when calling PCRE -to be osize. The default value is 45, which is enough for 14 capturing -subexpressions. The vector size can be changed for individual matching calls by -including \O in the data line (see below). -
---p -Behave as if each regex has /P modifier; the POSIX wrapper API is used -to call PCRE. None of the other options has any effect when -p is set. -
---t -Run each compile, study, and match many times with a timer, and output -resulting time per compile or match (in milliseconds). Do not set -t with --m, because you will then get the size output 20000 times and the timing -will be distorted. -
--If pcretest is given two filename arguments, it reads from the first and -writes to the second. If it is given only one filename argument, it reads from -that file and writes to stdout. Otherwise, it reads from stdin and writes to -stdout, and prompts for each line of input, using "re>" to prompt for regular -expressions, and "data>" to prompt for data lines. -
--The program handles any number of sets of input on a single input file. Each -set starts with a regular expression, and continues with any number of data -lines to be matched against the pattern. -
--Each line is matched separately and independently. If you want to do -multiple-line matches, you have to use the \n escape sequence in a single line -of input to encode the newline characters. The maximum length of data line is -30,000 characters. -
--An empty line signals the end of the data lines, at which point a new regular -expression is read. The regular expressions are given enclosed in any -non-alphameric delimiters other than backslash, for example -
--
- /(a|bc)x+yz/ -- -
-White space before the initial delimiter is ignored. A regular expression may -be continued over several input lines, in which case the newline characters are -included within it. It is possible to include the delimiter within the pattern -by escaping it, for example -
--
- /abc\/def/ -- -
-If you do so, the escape and the delimiter form part of the pattern, but since -delimiters are always non-alphameric, this does not affect its interpretation. -If the terminating delimiter is immediately followed by a backslash, for -example, -
--
- /abc/\ -- -
-then a backslash is added to the end of the pattern. This is done to provide a -way of testing the error condition that arises if a pattern finishes with a -backslash, because -
--
- /abc\/ -- -
-is interpreted as the first line of a pattern that starts with "abc/", causing -pcretest to read the next line as a continuation of the regular expression. -
--The pattern may be followed by i, m, s, or x to set the -PCRE_CASELESS, PCRE_MULTILINE, PCRE_DOTALL, or PCRE_EXTENDED options, -respectively. For example: -
--
- /caseless/i -- -
-These modifier letters have the same effect as they do in Perl. There are -others that set PCRE options that do not correspond to anything in Perl: -/A, /E, /N, /U, and /X set PCRE_ANCHORED, -PCRE_DOLLAR_ENDONLY, PCRE_NO_AUTO_CAPTURE, PCRE_UNGREEDY, and PCRE_EXTRA -respectively. -
--Searching for all possible matches within each subject string can be requested -by the /g or /G modifier. After finding a match, PCRE is called -again to search the remainder of the subject string. The difference between -/g and /G is that the former uses the startoffset argument to -pcre_exec() to start searching at a new point within the entire string -(which is in effect what Perl does), whereas the latter passes over a shortened -substring. This makes a difference to the matching process if the pattern -begins with a lookbehind assertion (including \b or \B). -
--If any call to pcre_exec() in a /g or /G sequence matches an -empty string, the next call is done with the PCRE_NOTEMPTY and PCRE_ANCHORED -flags set in order to search for another, non-empty, match at the same point. -If this second match fails, the start offset is advanced by one, and the normal -match is retried. This imitates the way Perl handles such cases when using the -/g modifier or the split() function. -
--There are a number of other modifiers for controlling the way pcretest -operates. -
--The /+ modifier requests that as well as outputting the substring that -matched the entire pattern, pcretest should in addition output the remainder of -the subject string. This is useful for tests where the subject contains -multiple copies of the same substring. -
--The /L modifier must be followed directly by the name of a locale, for -example, -
--
- /pattern/Lfr -- -
-For this reason, it must be the last modifier letter. The given locale is set, -pcre_maketables() is called to build a set of character tables for the -locale, and this is then passed to pcre_compile() when compiling the -regular expression. Without an /L modifier, NULL is passed as the tables -pointer; that is, /L applies only to the expression on which it appears. -
--The /I modifier requests that pcretest output information about the -compiled expression (whether it is anchored, has a fixed first character, and -so on). It does this by calling pcre_fullinfo() after compiling an -expression, and outputting the information it gets back. If the pattern is -studied, the results of that are also output. -
--The /D modifier is a PCRE debugging feature, which also assumes /I. -It causes the internal form of compiled regular expressions to be output after -compilation. If the pattern was studied, the information returned is also -output. -
--The /S modifier causes pcre_study() to be called after the -expression has been compiled, and the results used when the expression is -matched. -
--The /M modifier causes the size of memory block used to hold the compiled -pattern to be output. -
--The /P modifier causes pcretest to call PCRE via the POSIX wrapper -API rather than its native API. When this is done, all other modifiers except -/i, /m, and /+ are ignored. REG_ICASE is set if /i is -present, and REG_NEWLINE is set if /m is present. The wrapper functions -force PCRE_DOLLAR_ENDONLY always, and PCRE_DOTALL unless REG_NEWLINE is set. -
--The /8 modifier causes pcretest to call PCRE with the PCRE_UTF8 -option set. This turns on support for UTF-8 character handling in PCRE, -provided that it was compiled with this support enabled. This modifier also -causes any non-printing characters in output strings to be printed using the -\x{hh...} notation if they are valid UTF-8 sequences. -
--If the /? modifier is used with /8, it causes pcretest to -call pcre_compile() with the PCRE_NO_UTF8_CHECK option, to suppress the -checking of the string for UTF-8 validity. -
--If the pattern contains any callout requests, pcretest's callout function -will be called. By default, it displays the callout number, and the start and -current positions in the text at the callout time. For example, the output -
--
- --->pqrabcdef - 0 ^ ^ -- -
-indicates that callout number 0 occurred for a match attempt starting at the -fourth character of the subject string, when the pointer was at the seventh -character. The callout function returns zero (carry on matching) by default. -
--Inserting callouts may be helpful when using pcretest to check -complicated regular expressions. For further information about callouts, see -the -pcrecallout -documentation. -
--For testing the PCRE library, additional control of callout behaviour is -available via escape sequences in the data, as described in the following -section. In particular, it is possible to pass in a number as callout data (the -default is zero). If the callout function receives a non-zero number, it -returns that value instead of zero. -
--Before each data line is passed to pcre_exec(), leading and trailing -whitespace is removed, and it is then scanned for \ escapes. Some of these are -pretty esoteric features, intended for checking out some of the more -complicated features of PCRE. If you are just testing "ordinary" regular -expressions, you probably don't need any of these. The following escapes are -recognized: -
--
- \a alarm (= BEL) - \b backspace - \e escape - \f formfeed - \n newline - \r carriage return - \t tab - \v vertical tab - \nnn octal character (up to 3 octal digits) - \xhh hexadecimal character (up to 2 hex digits) - \x{hh...} hexadecimal character, any number of digits - in UTF-8 mode - \A pass the PCRE_ANCHORED option to pcre_exec() - \B pass the PCRE_NOTBOL option to pcre_exec() - \Cdd call pcre_copy_substring() for substring dd - after a successful match (any decimal number - less than 32) - \Cname call pcre_copy_named_substring() for substring - "name" after a successful match (name termin- - ated by next non alphanumeric character) - \C+ show the current captured substrings at callout - time - \C- do not supply a callout function - \C!n return 1 instead of 0 when callout number n is - reached - \C!n!m return 1 instead of 0 when callout number n is - reached for the nth time - \C*n pass the number n (may be negative) as callout - data - \Gdd call pcre_get_substring() for substring dd - after a successful match (any decimal number - less than 32) - \Gname call pcre_get_named_substring() for substring - "name" after a successful match (name termin- - ated by next non-alphanumeric character) - \L call pcre_get_substringlist() after a - successful match - \M discover the minimum MATCH_LIMIT setting - \N pass the PCRE_NOTEMPTY option to pcre_exec() - \Odd set the size of the output vector passed to - pcre_exec() to dd (any number of decimal - digits) - \S output details of memory get/free calls during matching - \Z pass the PCRE_NOTEOL option to pcre_exec() - \? pass the PCRE_NO_UTF8_CHECK option to - pcre_exec() -- -
-If \M is present, pcretest calls pcre_exec() several times, with -different values in the match_limit field of the pcre_extra data -structure, until it finds the minimum number that is needed for -pcre_exec() to complete. This number is a measure of the amount of -recursion and backtracking that takes place, and checking it out can be -instructive. For most simple matches, the number is quite small, but for -patterns with very large numbers of matching possibilities, it can become large -very quickly with increasing length of subject string. -
--When \O is used, it may be higher or lower than the size set by the -O -option (or defaulted to 45); \O applies only to the call of pcre_exec() -for the line in which it appears. -
--A backslash followed by anything else just escapes the anything else. If the -very last character is a backslash, it is ignored. This gives a way of passing -an empty line as data, since a real empty line terminates the data input. -
--If /P was present on the regex, causing the POSIX wrapper API to be used, -only \B, and \Z have any effect, causing REG_NOTBOL and REG_NOTEOL -to be passed to regexec() respectively. -
--The use of \x{hh...} to represent UTF-8 characters is not dependent on the use -of the /8 modifier on the pattern. It is recognized always. There may be -any number of hexadecimal digits inside the braces. The result is from one to -six bytes, encoded according to the UTF-8 rules. -
--When a match succeeds, pcretest outputs the list of captured substrings that -pcre_exec() returns, starting with number 0 for the string that matched -the whole pattern. Here is an example of an interactive pcretest run. -
--
- $ pcretest - PCRE version 4.00 08-Jan-2003 -- -
-
- re> /^abc(\d+)/ - data> abc123 - 0: abc123 - 1: 123 - data> xyz - No match -- -
-If the strings contain any non-printing characters, they are output as \0x -escapes, or as \x{...} escapes if the /8 modifier was present on the -pattern. If the pattern has the /+ modifier, then the output for -substring 0 is followed by the the rest of the subject string, identified by -"0+" like this: -
--
- re> /cat/+ - data> cataract - 0: cat - 0+ aract -- -
-If the pattern has the /g or /G modifier, the results of successive -matching attempts are output in sequence, like this: -
--
- re> /\Bi(\w\w)/g - data> Mississippi - 0: iss - 1: ss - 0: iss - 1: ss - 0: ipp - 1: pp -- -
-"No match" is output only if the first match attempt fails. -
--If any of the sequences \C, \G, or \L are present in a -data line that is successfully matched, the substrings extracted by the -convenience functions are output with C, G, or L after the string number -instead of a colon. This is in addition to the normal full list. The string -length (that is, the return from the extraction function) is given in -parentheses after each string for \C and \G. -
--Note that while patterns can be continued over several lines (a plain ">" -prompt is used for continuations), data lines may not. However newlines can be -included in data by means of the \n escape. -
-
-Philip Hazel <ph10@cam.ac.uk>
-
-University Computing Service,
-
-Cambridge CB2 3QG, England.
-
-Last updated: 09 December 2003
-
-Copyright © 1997-2003 University of Cambridge.
--
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