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diff --git a/external-libs/pcre/doc/pcretest.1 b/external-libs/pcre/doc/pcretest.1 new file mode 100644 index 00000000..f3d69c83 --- /dev/null +++ b/external-libs/pcre/doc/pcretest.1 @@ -0,0 +1,364 @@ +.TH PCRETEST 1 +.SH NAME +pcretest - a program for testing Perl-compatible regular expressions. +.SH SYNOPSIS +.B pcretest "[-d] [-i] [-m] [-o osize] [-p] [-t] [source] [destination]" + +\fBpcretest\fR 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 +.\" HREF +\fBpcrepattern\fR +.\" +documentation. For details of PCRE and its options, see the +.\" HREF +\fBpcreapi\fR +.\" +documentation. + +.SH OPTIONS +.rs +.sp +.TP 10 +\fB-C\fR +Output the version number of the PCRE library, and all available information +about the optional features that are included, and then exit. +.TP 10 +\fB-d\fR +Behave as if each regex had the \fB/D\fR modifier (see below); the internal +form is output after compilation. +.TP 10 +\fB-i\fR +Behave as if each regex had the \fB/I\fR modifier; information about the +compiled pattern is given after compilation. +.TP 10 +\fB-m\fR +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, \fB-s\fR is a synonym for \fB-m\fR. +.TP 10 +\fB-o\fR \fIosize\fR +Set the number of elements in the output vector that is used when calling PCRE +to be \fIosize\fR. 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). +.TP 10 +\fB-p\fR +Behave as if each regex has \fB/P\fR modifier; the POSIX wrapper API is used +to call PCRE. None of the other options has any effect when \fB-p\fR is set. +.TP 10 +\fB-t\fR +Run each compile, study, and match many times with a timer, and output +resulting time per compile or match (in milliseconds). Do not set \fB-t\fR with +\fB-m\fR, because you will then get the size output 20000 times and the timing +will be distorted. + +.SH DESCRIPTION +.rs +.sp +If \fBpcretest\fR 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. + +.SH PATTERN MODIFIERS +.rs +.sp +The pattern may be followed by \fBi\fR, \fBm\fR, \fBs\fR, or \fBx\fR 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: +\fB/A\fR, \fB/E\fR, \fB/N\fR, \fB/U\fR, and \fB/X\fR 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 \fB/g\fR or \fB/G\fR modifier. After finding a match, PCRE is called +again to search the remainder of the subject string. The difference between +\fB/g\fR and \fB/G\fR is that the former uses the \fIstartoffset\fR argument to +\fBpcre_exec()\fR 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 \fBpcre_exec()\fR in a \fB/g\fR or \fB/G\fR 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 +\fB/g\fR modifier or the \fBsplit()\fR function. + +There are a number of other modifiers for controlling the way \fBpcretest\fR +operates. + +The \fB/+\fR 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 \fB/L\fR 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, +\fBpcre_maketables()\fR is called to build a set of character tables for the +locale, and this is then passed to \fBpcre_compile()\fR when compiling the +regular expression. Without an \fB/L\fR modifier, NULL is passed as the tables +pointer; that is, \fB/L\fR applies only to the expression on which it appears. + +The \fB/I\fR modifier requests that \fBpcretest\fR output information about the +compiled expression (whether it is anchored, has a fixed first character, and +so on). It does this by calling \fBpcre_fullinfo()\fR after compiling an +expression, and outputting the information it gets back. If the pattern is +studied, the results of that are also output. + +The \fB/D\fR modifier is a PCRE debugging feature, which also assumes \fB/I\fR. +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 \fB/S\fR modifier causes \fBpcre_study()\fR to be called after the +expression has been compiled, and the results used when the expression is +matched. + +The \fB/M\fR modifier causes the size of memory block used to hold the compiled +pattern to be output. + +The \fB/P\fR modifier causes \fBpcretest\fR to call PCRE via the POSIX wrapper +API rather than its native API. When this is done, all other modifiers except +\fB/i\fR, \fB/m\fR, and \fB/+\fR are ignored. REG_ICASE is set if \fB/i\fR is +present, and REG_NEWLINE is set if \fB/m\fR is present. The wrapper functions +force PCRE_DOLLAR_ENDONLY always, and PCRE_DOTALL unless REG_NEWLINE is set. + +The \fB/8\fR modifier causes \fBpcretest\fR 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 \fB/?\fR modifier is used with \fB/8\fR, it causes \fBpcretest\fR to +call \fBpcre_compile()\fR with the PCRE_NO_UTF8_CHECK option, to suppress the +checking of the string for UTF-8 validity. + +.SH CALLOUTS +.rs +.sp +If the pattern contains any callout requests, \fBpcretest\fR'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 \fBpcretest\fR to check +complicated regular expressions. For further information about callouts, see +the +.\" HREF +\fBpcrecallout\fR +.\" +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. + +.SH DATA LINES +.rs +.sp +Before each data line is passed to \fBpcre_exec()\fR, 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 \fBpcre_exec()\fR + \\B pass the PCRE_NOTBOL option to \fBpcre_exec()\fR + \\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 \fBpcre_exec()\fR + \\Odd set the size of the output vector passed to + \fBpcre_exec()\fR to dd (any number of decimal + digits) + \\S output details of memory get/free calls during matching + \\Z pass the PCRE_NOTEOL option to \fBpcre_exec()\fR + \\? pass the PCRE_NO_UTF8_CHECK option to + \fBpcre_exec()\fR + +If \\M is present, \fBpcretest\fR calls \fBpcre_exec()\fR several times, with +different values in the \fImatch_limit\fR field of the \fBpcre_extra\fR data +structure, until it finds the minimum number that is needed for +\fBpcre_exec()\fR 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 \fB-O\fR +option (or defaulted to 45); \\O applies only to the call of \fBpcre_exec()\fR +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 \fB/P\fR was present on the regex, causing the POSIX wrapper API to be used, +only \fB\B\fR, and \fB\Z\fR have any effect, causing REG_NOTBOL and REG_NOTEOL +to be passed to \fBregexec()\fR respectively. + +The use of \\x{hh...} to represent UTF-8 characters is not dependent on the use +of the \fB/8\fR 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. + +.SH OUTPUT FROM PCRETEST +.rs +.sp +When a match succeeds, pcretest outputs the list of captured substrings that +\fBpcre_exec()\fR 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 \fB/8\fR modifier was present on the +pattern. If the pattern has the \fB/+\fR 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 \fB/g\fR or \fB/G\fR 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 \fB\\C\fR, \fB\\G\fR, or \fB\\L\fR 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 \fB\\C\fR and \fB\\G\fR. + +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. + +.SH AUTHOR +.rs +.sp +Philip Hazel <ph10@cam.ac.uk> +.br +University Computing Service, +.br +Cambridge CB2 3QG, England. + +.in 0 +Last updated: 09 December 2003 +.br +Copyright (c) 1997-2003 University of Cambridge. |