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diff --git a/external-libs/pcre/doc/pcreapi.3 b/external-libs/pcre/doc/pcreapi.3 deleted file mode 100644 index 4c7d43c3..00000000 --- a/external-libs/pcre/doc/pcreapi.3 +++ /dev/null @@ -1,1082 +0,0 @@ -.TH PCRE 3 -.SH NAME -PCRE - Perl-compatible regular expressions -.SH SYNOPSIS OF PCRE API -.rs -.sp -.B #include <pcre.h> -.PP -.SM -.br -.B pcre *pcre_compile(const char *\fIpattern\fR, int \fIoptions\fR, -.ti +5n -.B const char **\fIerrptr\fR, int *\fIerroffset\fR, -.ti +5n -.B const unsigned char *\fItableptr\fR); -.PP -.br -.B pcre_extra *pcre_study(const pcre *\fIcode\fR, int \fIoptions\fR, -.ti +5n -.B const char **\fIerrptr\fR); -.PP -.br -.B int pcre_exec(const pcre *\fIcode\fR, "const pcre_extra *\fIextra\fR," -.ti +5n -.B "const char *\fIsubject\fR," int \fIlength\fR, int \fIstartoffset\fR, -.ti +5n -.B int \fIoptions\fR, int *\fIovector\fR, int \fIovecsize\fR); -.PP -.br -.B int pcre_copy_named_substring(const pcre *\fIcode\fR, -.ti +5n -.B const char *\fIsubject\fR, int *\fIovector\fR, -.ti +5n -.B int \fIstringcount\fR, const char *\fIstringname\fR, -.ti +5n -.B char *\fIbuffer\fR, int \fIbuffersize\fR); -.PP -.br -.B int pcre_copy_substring(const char *\fIsubject\fR, int *\fIovector\fR, -.ti +5n -.B int \fIstringcount\fR, int \fIstringnumber\fR, char *\fIbuffer\fR, -.ti +5n -.B int \fIbuffersize\fR); -.PP -.br -.B int pcre_get_named_substring(const pcre *\fIcode\fR, -.ti +5n -.B const char *\fIsubject\fR, int *\fIovector\fR, -.ti +5n -.B int \fIstringcount\fR, const char *\fIstringname\fR, -.ti +5n -.B const char **\fIstringptr\fR); -.PP -.br -.B int pcre_get_stringnumber(const pcre *\fIcode\fR, -.ti +5n -.B const char *\fIname\fR); -.PP -.br -.B int pcre_get_substring(const char *\fIsubject\fR, int *\fIovector\fR, -.ti +5n -.B int \fIstringcount\fR, int \fIstringnumber\fR, -.ti +5n -.B const char **\fIstringptr\fR); -.PP -.br -.B int pcre_get_substring_list(const char *\fIsubject\fR, -.ti +5n -.B int *\fIovector\fR, int \fIstringcount\fR, "const char ***\fIlistptr\fR);" -.PP -.br -.B void pcre_free_substring(const char *\fIstringptr\fR); -.PP -.br -.B void pcre_free_substring_list(const char **\fIstringptr\fR); -.PP -.br -.B const unsigned char *pcre_maketables(void); -.PP -.br -.B int pcre_fullinfo(const pcre *\fIcode\fR, "const pcre_extra *\fIextra\fR," -.ti +5n -.B int \fIwhat\fR, void *\fIwhere\fR); -.PP -.br -.B int pcre_info(const pcre *\fIcode\fR, int *\fIoptptr\fR, int -.B *\fIfirstcharptr\fR); -.PP -.br -.B int pcre_config(int \fIwhat\fR, void *\fIwhere\fR); -.PP -.br -.B char *pcre_version(void); -.PP -.br -.B void *(*pcre_malloc)(size_t); -.PP -.br -.B void (*pcre_free)(void *); -.PP -.br -.B void *(*pcre_stack_malloc)(size_t); -.PP -.br -.B void (*pcre_stack_free)(void *); -.PP -.br -.B int (*pcre_callout)(pcre_callout_block *); - -.SH PCRE API -.rs -.sp -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 \fBpcreposix\fR documentation. - -The native API function prototypes are defined in the header file \fBpcre.h\fR, -and on Unix systems the library itself is called \fBlibpcre.a\fR, so can be -accessed by adding \fB-lpcre\fR 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 \fBpcre_compile()\fR, \fBpcre_study()\fR, and \fBpcre_exec()\fR -are used for compiling and matching regular expressions. A sample program that -demonstrates the simplest way of using them is given in the file -\fIpcredemo.c\fR. The \fBpcresample\fR documentation describes how to run it. - -There are convenience functions for extracting captured substrings from a -matched subject string. They are: - - \fBpcre_copy_substring()\fR - \fBpcre_copy_named_substring()\fR - \fBpcre_get_substring()\fR - \fBpcre_get_named_substring()\fR - \fBpcre_get_substring_list()\fR - -\fBpcre_free_substring()\fR and \fBpcre_free_substring_list()\fR are also -provided, to free the memory used for extracted strings. - -The function \fBpcre_maketables()\fR is used (optionally) to build a set of -character tables in the current locale for passing to \fBpcre_compile()\fR. - -The function \fBpcre_fullinfo()\fR is used to find out information about a -compiled pattern; \fBpcre_info()\fR is an obsolete version which returns only -some of the available information, but is retained for backwards compatibility. -The function \fBpcre_version()\fR returns a pointer to a string containing the -version of PCRE and its date of release. - -The global variables \fBpcre_malloc\fR and \fBpcre_free\fR initially contain -the entry points of the standard \fBmalloc()\fR and \fBfree()\fR 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 \fBpcre_stack_malloc\fR and \fBpcre_stack_free\fR 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 \fBpcre_callout\fR 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 \fBpcrecallout\fR -documentation. - -.SH MULTITHREADING -.rs -.sp -The PCRE functions can be used in multi-threading applications, with the -proviso that the memory management functions pointed to by \fBpcre_malloc\fR, -\fBpcre_free\fR, \fBpcre_stack_malloc\fR, and \fBpcre_stack_free\fR, and the -callout function pointed to by \fBpcre_callout\fR, 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. - -.SH CHECKING BUILD-TIME OPTIONS -.rs -.sp -.B int pcre_config(int \fIwhat\fR, void *\fIwhere\fR); -.PP -The function \fBpcre_config()\fR makes it possible for a PCRE client to -discover which optional features have been compiled into the PCRE library. The -.\" HREF -\fBpcrebuild\fR -.\" -documentation has more details about these optional features. - -The first argument for \fBpcre_config()\fR 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 \fBmalloc()\fR for output vectors. Further details are given in -the \fBpcreposix\fR 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 \fBpcre_exec()\fR execution. Further -details are given with \fBpcre_exec()\fR 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, \fBpcre_stack_malloc\fR and \fBpcre_stack_free\fR are -called to manage memory blocks on the heap, thus avoiding the use of the stack. - -.SH COMPILING A PATTERN -.rs -.sp -.B pcre *pcre_compile(const char *\fIpattern\fR, int \fIoptions\fR, -.ti +5n -.B const char **\fIerrptr\fR, int *\fIerroffset\fR, -.ti +5n -.B const unsigned char *\fItableptr\fR); -.PP - -The function \fBpcre_compile()\fR 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 \fIpattern\fR. A pointer to a single block of memory -that is obtained via \fBpcre_malloc\fR is returned. This contains the compiled -code and related data. The \fBpcre\fR 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 \fBpcre\fR data block is not -fully relocatable, because it contains a copy of the \fItableptr\fR argument, -which is an address (see below). - -The \fIoptions\fR 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 \fBpcrepattern\fR documentation). For these options, the contents of the -\fIoptions\fR 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 \fIerrptr\fR is NULL, \fBpcre_compile()\fR returns NULL immediately. -Otherwise, if compilation of a pattern fails, \fBpcre_compile()\fR returns -NULL, and sets the variable pointed to by \fIerrptr\fR 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 -\fIerroffset\fR, which must not be NULL. If it is, an immediate error is given. - -If the final argument, \fItableptr\fR, is NULL, PCRE uses a default set of -character tables which are built when it is compiled, using the default C -locale. Otherwise, \fItableptr\fR must be the result of a call to -\fBpcre_maketables()\fR. See the section on locale support below. - -This code fragment shows a typical straightforward call to \fBpcre_compile()\fR: - - 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 -.\" HTML <a href="pcre.html#utf8support"> -.\" </a> -section on UTF-8 support -.\" -in the main -.\" HREF -\fBpcre\fR -.\" -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, -\fBpcre_compile()\fR 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 \fBpcre_exec()\fR. - - -.SH STUDYING A PATTERN -.rs -.sp -.B pcre_extra *pcre_study(const pcre *\fIcode\fR, int \fIoptions\fR, -.ti +5n -.B const char **\fIerrptr\fR); -.PP -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 \fBpcre_study()\fR takes a pointer to a compiled pattern as its first -argument. If studing the pattern produces additional information that will help -speed up matching, \fBpcre_study()\fR returns a pointer to a \fBpcre_extra\fR -block, in which the \fIstudy_data\fR field points to the results of the study. - -The returned value from a \fBpcre_study()\fR can be passed directly to -\fBpcre_exec()\fR. However, the \fBpcre_extra\fR 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, \fBpcre_study()\fR returns NULL. In that circumstance, if the -calling program wants to pass some of the other fields to \fBpcre_exec()\fR, it -must set up its own \fBpcre_extra\fR block. - -The second argument contains option bits. At present, no options are defined -for \fBpcre_study()\fR, and this argument should always be zero. - -The third argument for \fBpcre_study()\fR 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 \fBpcre_study()\fR, to -be sure that it has run successfully. - -This is a typical call to \fBpcre_study\fR(): - - 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. - -.\" HTML <a name="localesupport"></a> -.SH LOCALE SUPPORT -.rs -.sp -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 \fBpcre_compile()\fR -is NULL, and is sufficient for many applications. - -An alternative set of tables can, however, be supplied. Such tables are built -by calling the \fBpcre_maketables()\fR function, which has no arguments, in the -relevant locale. The result can then be passed to \fBpcre_compile()\fR 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 \fBpcre_malloc\fR. The -pointer that is passed to \fBpcre_compile\fR is saved with the compiled -pattern, and the same tables are used via this pointer by \fBpcre_study()\fR -and \fBpcre_exec()\fR. 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. - -.SH INFORMATION ABOUT A PATTERN -.rs -.sp -.B int pcre_fullinfo(const pcre *\fIcode\fR, "const pcre_extra *\fIextra\fR," -.ti +5n -.B int \fIwhat\fR, void *\fIwhere\fR); -.PP -The \fBpcre_fullinfo()\fR function returns information about a compiled -pattern. It replaces the obsolete \fBpcre_info()\fR function, which is -nevertheless retained for backwards compability (and is documented below). - -The first argument for \fBpcre_fullinfo()\fR is a pointer to the compiled -pattern. The second argument is the result of \fBpcre_study()\fR, 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 \fIcode\fR was NULL - the argument \fIwhere\fR was NULL - PCRE_ERROR_BADMAGIC the "magic number" was not found - PCRE_ERROR_BADOPTION the value of \fIwhat\fR was invalid - -Here is a typical call of \fBpcre_fullinfo()\fR, 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 \fBpcre.h\fR, 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 \fBint\fR 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 \fIwhere\fR. 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 \fBunsigned char *\fR 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 \fBint\fR 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 \fBpcre_exec()\fR 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 \fBint\fR 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 \fBchar\fR). 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 \fBunsigned long int\fR variable. These option bits -are those specified in the call to \fBpcre_compile()\fR, 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 -\fBpcre_fullinfo()\fR. - - PCRE_INFO_SIZE - -Return the size of the compiled pattern, that is, the value that was passed as -the argument to \fBpcre_malloc()\fR when PCRE was getting memory in which to -place the compiled data. The fourth argument should point to a \fBsize_t\fR -variable. - - PCRE_INFO_STUDYSIZE - -Returns the size of the data block pointed to by the \fIstudy_data\fR field in -a \fBpcre_extra\fR block. That is, it is the value that was passed to -\fBpcre_malloc()\fR when PCRE was getting memory into which to place the data -created by \fBpcre_study()\fR. The fourth argument should point to a -\fBsize_t\fR variable. - -.SH OBSOLETE INFO FUNCTION -.rs -.sp -.B int pcre_info(const pcre *\fIcode\fR, int *\fIoptptr\fR, int -.B *\fIfirstcharptr\fR); -.PP -The \fBpcre_info()\fR function is now obsolete because its interface is too -restrictive to return all the available data about a compiled pattern. New -programs should use \fBpcre_fullinfo()\fR instead. The yield of -\fBpcre_info()\fR is the number of capturing subpatterns, or one of the -following negative numbers: - - PCRE_ERROR_NULL the argument \fIcode\fR was NULL - PCRE_ERROR_BADMAGIC the "magic number" was not found - -If the \fIoptptr\fR 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 \fIfirstcharptr\fR argument is not NULL, -it is used to pass back information about the first character of any matched -string (see PCRE_INFO_FIRSTBYTE above). - -.SH MATCHING A PATTERN -.rs -.sp -.B int pcre_exec(const pcre *\fIcode\fR, "const pcre_extra *\fIextra\fR," -.ti +5n -.B "const char *\fIsubject\fR," int \fIlength\fR, int \fIstartoffset\fR, -.ti +5n -.B int \fIoptions\fR, int *\fIovector\fR, int \fIovecsize\fR); -.PP -The function \fBpcre_exec()\fR is called to match a subject string against a -pre-compiled pattern, which is passed in the \fIcode\fR argument. If the -pattern has been studied, the result of the study should be passed in the -\fIextra\fR argument. - -Here is an example of a simple call to \fBpcre_exec()\fR: - - 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 \fIextra\fR argument is not NULL, it must point to a \fBpcre_extra\fR -data block. The \fBpcre_study()\fR 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 \fIflags\fR; - void *\fIstudy_data\fR; - unsigned long int \fImatch_limit\fR; - void *\fIcallout_data\fR; - -The \fIflags\fR 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 \fIstudy_data\fR field is set in the -\fBpcre_extra\fR block that is returned by \fBpcre_study()\fR, 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 \fImatch_limit\fR 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 \fBmatch()\fR 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 \fBpcre_exec()\fR with a \fRpcre_extra\fR block -in which \fImatch_limit\fR is set to a smaller value, and -PCRE_EXTRA_MATCH_LIMIT is set in the \fIflags\fR field. If the limit is -exceeded, \fBpcre_exec()\fR returns PCRE_ERROR_MATCHLIMIT. - -The \fIpcre_callout\fR field is used in conjunction with the "callout" feature, -which is described in the \fBpcrecallout\fR documentation. - -The PCRE_ANCHORED option can be passed in the \fIoptions\fR argument, whose -unused bits must be zero. This limits \fBpcre_exec()\fR 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 \fIstartoffset\fR 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, \fBpcre_exec()\fR returns the error -PCRE_ERROR_BADUTF8. If \fIstartoffset\fR 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 \fBpcre_exec()\fR. You might want to do this for the second and -subsequent calls to \fBpcre_exec()\fR 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 \fIstartoffset\fR 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 \fIstartoffset\fR 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 \fBsplit()\fR 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 \fBpcre_exec()\fR as a pointer in -\fIsubject\fR, a length in \fIlength\fR, and a starting byte offset in -\fIstartoffset\fR. 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 \fBpcre_exec()\fR again after a previous success. -Setting \fIstartoffset\fR 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 \fBpcre_exec()\fR finds the first -occurrence. If \fBpcre_exec()\fR 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 -\fBpcre_exec()\fR is passed the entire string again, but with \fIstartoffset\fR -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 \fIovector\fR. The number of elements in the vector -is passed in \fIovecsize\fR. 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 \fBpcre_exec()\fR while -matching capturing subpatterns, and is not available for passing back -information. The length passed in \fIovecsize\fR 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 \fIovector\fR, 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, \fIovector[0]\fR and \fIovector[1]\fR, 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 \fBpcre_exec()\fR -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 \fIn+1\fR to match some -part of the subject when subpattern \fIn\fR 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, -\fBpcre_exec()\fR may be called with \fIovector\fR passed as NULL and -\fIovecsize\fR as zero. However, if the pattern contains back references and -the \fIovector\fR 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 \fIovector\fR. - -Note that \fBpcre_info()\fR can be used to find out how many capturing -subpatterns there are in a compiled pattern. The smallest size for -\fIovector\fR that will allow for \fIn\fR captured substrings, in addition to -the offsets of the substring matched by the whole pattern, is (\fIn\fR+1)*3. - -If \fBpcre_exec()\fR 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 \fIcode\fR or \fIsubject\fR was passed as NULL, or \fIovector\fR was -NULL and \fIovecsize\fR was not zero. - - PCRE_ERROR_BADOPTION (-3) - -An unrecognized bit was set in the \fIoptions\fR 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 \fIovector\fR that is passed to -\fBpcre_exec()\fR 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 \fBpcre_malloc()\fR fails, this error is given. The memory is freed at -the end of matching. - - PCRE_ERROR_NOSUBSTRING (-7) - -This error is used by the \fBpcre_copy_substring()\fR, -\fBpcre_get_substring()\fR, and \fBpcre_get_substring_list()\fR functions (see -below). It is never returned by \fBpcre_exec()\fR. - - PCRE_ERROR_MATCHLIMIT (-8) - -The recursion and backtracking limit, as specified by the \fImatch_limit\fR -field in a \fBpcre_extra\fR structure (or defaulted) was reached. See the -description above. - - PCRE_ERROR_CALLOUT (-9) - -This error is never generated by \fBpcre_exec()\fR itself. It is provided for -use by callout functions that want to yield a distinctive error code. See the -\fBpcrecallout\fR 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 \fIstartoffset\fR did not point to the beginning of a UTF-8 character. - -.SH EXTRACTING CAPTURED SUBSTRINGS BY NUMBER -.rs -.sp -.B int pcre_copy_substring(const char *\fIsubject\fR, int *\fIovector\fR, -.ti +5n -.B int \fIstringcount\fR, int \fIstringnumber\fR, char *\fIbuffer\fR, -.ti +5n -.B int \fIbuffersize\fR); -.PP -.br -.B int pcre_get_substring(const char *\fIsubject\fR, int *\fIovector\fR, -.ti +5n -.B int \fIstringcount\fR, int \fIstringnumber\fR, -.ti +5n -.B const char **\fIstringptr\fR); -.PP -.br -.B int pcre_get_substring_list(const char *\fIsubject\fR, -.ti +5n -.B int *\fIovector\fR, int \fIstringcount\fR, "const char ***\fIlistptr\fR);" -.PP -Captured substrings can be accessed directly by using the offsets returned by -\fBpcre_exec()\fR in \fIovector\fR. For convenience, the functions -\fBpcre_copy_substring()\fR, \fBpcre_get_substring()\fR, and -\fBpcre_get_substring_list()\fR 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: -\fIsubject\fR is the subject string which has just been successfully matched, -\fIovector\fR is a pointer to the vector of integer offsets that was passed to -\fBpcre_exec()\fR, and \fIstringcount\fR 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 \fBpcre_exec\fR if it is greater than -zero. If \fBpcre_exec()\fR returned zero, indicating that it ran out of space -in \fIovector\fR, the value passed as \fIstringcount\fR should be the size of -the vector divided by three. - -The functions \fBpcre_copy_substring()\fR and \fBpcre_get_substring()\fR -extract a single substring, whose number is given as \fIstringnumber\fR. A -value of zero extracts the substring that matched the entire pattern, while -higher values extract the captured substrings. For \fBpcre_copy_substring()\fR, -the string is placed in \fIbuffer\fR, whose length is given by -\fIbuffersize\fR, while for \fBpcre_get_substring()\fR a new block of memory is -obtained via \fBpcre_malloc\fR, and its address is returned via -\fIstringptr\fR. 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 \fBpcre_copy_substring()\fR, or the attempt to get -memory failed for \fBpcre_get_substring()\fR. - - PCRE_ERROR_NOSUBSTRING (-7) - -There is no substring whose number is \fIstringnumber\fR. - -The \fBpcre_get_substring_list()\fR 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 \fBpcre_malloc\fR. The address of the memory block -is returned via \fIlistptr\fR, 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 \fIn+1\fR matches some part of the -subject, but subpattern \fIn\fR 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 \fIovector\fR, which is negative for unset -substrings. - -The two convenience functions \fBpcre_free_substring()\fR and -\fBpcre_free_substring_list()\fR can be used to free the memory returned by -a previous call of \fBpcre_get_substring()\fR or -\fBpcre_get_substring_list()\fR, respectively. They do nothing more than call -the function pointed to by \fBpcre_free\fR, 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 -\fBpcre_free\fR directly; it is for these cases that the functions are -provided. - -.SH EXTRACTING CAPTURED SUBSTRINGS BY NAME -.rs -.sp -.B int pcre_copy_named_substring(const pcre *\fIcode\fR, -.ti +5n -.B const char *\fIsubject\fR, int *\fIovector\fR, -.ti +5n -.B int \fIstringcount\fR, const char *\fIstringname\fR, -.ti +5n -.B char *\fIbuffer\fR, int \fIbuffersize\fR); -.PP -.br -.B int pcre_get_stringnumber(const pcre *\fIcode\fR, -.ti +5n -.B const char *\fIname\fR); -.PP -.br -.B int pcre_get_named_substring(const pcre *\fIcode\fR, -.ti +5n -.B const char *\fIsubject\fR, int *\fIovector\fR, -.ti +5n -.B int \fIstringcount\fR, const char *\fIstringname\fR, -.ti +5n -.B const char **\fIstringptr\fR); -.PP -To extract a substring by name, you first have to find associated number. This -can be done by calling \fBpcre_get_stringnumber()\fR. 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 \fIpcre_copy_named_substring()\fR and -\fIpcre_get_named_substring()\fR 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 \fBpcre_get_stringnumber()\fR, and if it succeeds, they -then call \fIpcre_copy_substring()\fR or \fIpcre_get_substring()\fR, as -appropriate. - -.in 0 -Last updated: 09 December 2003 -.br -Copyright (c) 1997-2003 University of Cambridge. |