pcretest specification

From 582b500cd996c96054615870fd13d6ab0ea77428 Mon Sep 17 00:00:00 2001 From: Jay Berkenbilt Date: Sat, 10 Oct 2009 15:10:05 +0000 Subject: start integrating windows port git-svn-id: svn+q:///qpdf/trunk@757 71b93d88-0707-0410-a8cf-f5a4172ac649 --- external-libs/pcre/doc/html/pcretest.html | 443 ++++++++++++++++++++++++++++++ 1 file changed, 443 insertions(+) create mode 100644 external-libs/pcre/doc/html/pcretest.html (limited to 'external-libs/pcre/doc/html/pcretest.html') diff --git a/external-libs/pcre/doc/html/pcretest.html b/external-libs/pcre/doc/html/pcretest.html new file mode 100644 index 00000000..2ba9893d --- /dev/null +++ b/external-libs/pcre/doc/html/pcretest.html @@ -0,0 +1,443 @@ + + +pcretest specification + + +This HTML document has been generated automatically from the original man page. +If there is any nonsense in it, please consult the man page, in case the +conversion went wrong.
+

SYNOPSIS +
OPTIONS +
DESCRIPTION +
PATTERN MODIFIERS +
CALLOUTS +
DATA LINES +
OUTPUT FROM PCRETEST +
AUTHOR +

+
SYNOPSIS
+

+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. +

+
OPTIONS
+

+-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. +

+
DESCRIPTION
+

+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. +

+
PATTERN MODIFIERS
+

+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. +

+
CALLOUTS
+

+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. +

+
DATA LINES
+

+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. +

+
OUTPUT FROM PCRETEST
+

+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. +

+
AUTHOR
+

+Philip Hazel <ph10@cam.ac.uk> +
+University Computing Service, +
+Cambridge CB2 3QG, England. +