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diff --git a/doc/pcretest.1 b/doc/pcretest.1 new file mode 100644 index 0000000..92640da --- /dev/null +++ b/doc/pcretest.1 @@ -0,0 +1,1156 @@ +.TH PCRETEST 1 "09 February 2014" "PCRE 8.35" +.SH NAME +pcretest - a program for testing Perl-compatible regular expressions. +.SH SYNOPSIS +.rs +.sp +.B pcretest "[options] [input file [output file]]" +.sp +\fBpcretest\fP 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\fP +.\" +documentation. For details of the PCRE library function calls and their +options, see the +.\" HREF +\fBpcreapi\fP +.\" +, +.\" HREF +\fBpcre16\fP +and +.\" HREF +\fBpcre32\fP +.\" +documentation. +.P +The input for \fBpcretest\fP is a sequence of regular expression patterns and +strings to be matched, as described below. The output shows the result of each +match. Options on the command line and the patterns control PCRE options and +exactly what is output. +.P +As PCRE has evolved, it has acquired many different features, and as a result, +\fBpcretest\fP now has rather a lot of obscure options for testing every +possible feature. Some of these options are specifically designed for use in +conjunction with the test script and data files that are distributed as part of +PCRE, and are unlikely to be of use otherwise. They are all documented here, +but without much justification. +. +. +.SH "INPUT DATA FORMAT" +.rs +.sp +Input to \fBpcretest\fP is processed line by line, either by calling the C +library's \fBfgets()\fP function, or via the \fBlibreadline\fP library (see +below). In Unix-like environments, \fBfgets()\fP treats any bytes other than +newline as data characters. However, in some Windows environments character 26 +(hex 1A) causes an immediate end of file, and no further data is read. For +maximum portability, therefore, it is safest to use only ASCII characters in +\fBpcretest\fP input files. +. +. +.SH "PCRE's 8-BIT, 16-BIT AND 32-BIT LIBRARIES" +.rs +.sp +From release 8.30, two separate PCRE libraries can be built. The original one +supports 8-bit character strings, whereas the newer 16-bit library supports +character strings encoded in 16-bit units. From release 8.32, a third library +can be built, supporting character strings encoded in 32-bit units. The +\fBpcretest\fP program can be used to test all three libraries. However, it is +itself still an 8-bit program, reading 8-bit input and writing 8-bit output. +When testing the 16-bit or 32-bit library, the patterns and data strings are +converted to 16- or 32-bit format before being passed to the PCRE library +functions. Results are converted to 8-bit for output. +.P +References to functions and structures of the form \fBpcre[16|32]_xx\fP below +mean "\fBpcre_xx\fP when using the 8-bit library, \fBpcre16_xx\fP when using +the 16-bit library, or \fBpcre32_xx\fP when using the 32-bit library". +. +. +.SH "COMMAND LINE OPTIONS" +.rs +.TP 10 +\fB-8\fP +If both the 8-bit library has been built, this option causes the 8-bit library +to be used (which is the default); if the 8-bit library has not been built, +this option causes an error. +.TP 10 +\fB-16\fP +If both the 8-bit or the 32-bit, and the 16-bit libraries have been built, this +option causes the 16-bit library to be used. If only the 16-bit library has been +built, this is the default (so has no effect). If only the 8-bit or the 32-bit +library has been built, this option causes an error. +.TP 10 +\fB-32\fP +If both the 8-bit or the 16-bit, and the 32-bit libraries have been built, this +option causes the 32-bit library to be used. If only the 32-bit library has been +built, this is the default (so has no effect). If only the 8-bit or the 16-bit +library has been built, this option causes an error. +.TP 10 +\fB-b\fP +Behave as if each pattern has the \fB/B\fP (show byte code) modifier; the +internal form is output after compilation. +.TP 10 +\fB-C\fP +Output the version number of the PCRE library, and all available information +about the optional features that are included, and then exit with zero exit +code. All other options are ignored. +.TP 10 +\fB-C\fP \fIoption\fP +Output information about a specific build-time option, then exit. This +functionality is intended for use in scripts such as \fBRunTest\fP. The +following options output the value and set the exit code as indicated: +.sp + ebcdic-nl the code for LF (= NL) in an EBCDIC environment: + 0x15 or 0x25 + 0 if used in an ASCII environment + exit code is always 0 + linksize the configured internal link size (2, 3, or 4) + exit code is set to the link size + newline the default newline setting: + CR, LF, CRLF, ANYCRLF, or ANY + exit code is always 0 + bsr the default setting for what \eR matches: + ANYCRLF or ANY + exit code is always 0 +.sp +The following options output 1 for true or 0 for false, and set the exit code +to the same value: +.sp + ebcdic compiled for an EBCDIC environment + jit just-in-time support is available + pcre16 the 16-bit library was built + pcre32 the 32-bit library was built + pcre8 the 8-bit library was built + ucp Unicode property support is available + utf UTF-8 and/or UTF-16 and/or UTF-32 support + is available +.sp +If an unknown option is given, an error message is output; the exit code is 0. +.TP 10 +\fB-d\fP +Behave as if each pattern has the \fB/D\fP (debug) modifier; the internal +form and information about the compiled pattern is output after compilation; +\fB-d\fP is equivalent to \fB-b -i\fP. +.TP 10 +\fB-dfa\fP +Behave as if each data line contains the \eD escape sequence; this causes the +alternative matching function, \fBpcre[16|32]_dfa_exec()\fP, to be used instead +of the standard \fBpcre[16|32]_exec()\fP function (more detail is given below). +.TP 10 +\fB-help\fP +Output a brief summary these options and then exit. +.TP 10 +\fB-i\fP +Behave as if each pattern has the \fB/I\fP modifier; information about the +compiled pattern is given after compilation. +.TP 10 +\fB-M\fP +Behave as if each data line contains the \eM escape sequence; this causes +PCRE to discover the minimum MATCH_LIMIT and MATCH_LIMIT_RECURSION settings by +calling \fBpcre[16|32]_exec()\fP repeatedly with different limits. +.TP 10 +\fB-m\fP +Output the size of each compiled pattern after it has been compiled. This is +equivalent to adding \fB/M\fP to each regular expression. The size is given in +bytes for both libraries. +.TP 10 +\fB-O\fP +Behave as if each pattern has the \fB/O\fP modifier, that is disable +auto-possessification for all patterns. +.TP 10 +\fB-o\fP \fIosize\fP +Set the number of elements in the output vector that is used when calling +\fBpcre[16|32]_exec()\fP or \fBpcre[16|32]_dfa_exec()\fP to be \fIosize\fP. The +default value is 45, which is enough for 14 capturing subexpressions for +\fBpcre[16|32]_exec()\fP or 22 different matches for +\fBpcre[16|32]_dfa_exec()\fP. +The vector size can be changed for individual matching calls by including \eO +in the data line (see below). +.TP 10 +\fB-p\fP +Behave as if each pattern has the \fB/P\fP modifier; the POSIX wrapper API is +used to call PCRE. None of the other options has any effect when \fB-p\fP is +set. This option can be used only with the 8-bit library. +.TP 10 +\fB-q\fP +Do not output the version number of \fBpcretest\fP at the start of execution. +.TP 10 +\fB-S\fP \fIsize\fP +On Unix-like systems, set the size of the run-time stack to \fIsize\fP +megabytes. +.TP 10 +\fB-s\fP or \fB-s+\fP +Behave as if each pattern has the \fB/S\fP modifier; in other words, force each +pattern to be studied. If \fB-s+\fP is used, all the JIT compile options are +passed to \fBpcre[16|32]_study()\fP, causing just-in-time optimization to be set +up if it is available, for both full and partial matching. Specific JIT compile +options can be selected by following \fB-s+\fP with a digit in the range 1 to +7, which selects the JIT compile modes as follows: +.sp + 1 normal match only + 2 soft partial match only + 3 normal match and soft partial match + 4 hard partial match only + 6 soft and hard partial match + 7 all three modes (default) +.sp +If \fB-s++\fP is used instead of \fB-s+\fP (with or without a following digit), +the text "(JIT)" is added to the first output line after a match or no match +when JIT-compiled code was actually used. +.sp +Note that there are pattern options that can override \fB-s\fP, either +specifying no studying at all, or suppressing JIT compilation. +.sp +If the \fB/I\fP or \fB/D\fP option is present on a pattern (requesting output +about the compiled pattern), information about the result of studying is not +included when studying is caused only by \fB-s\fP and neither \fB-i\fP nor +\fB-d\fP is present on the command line. This behaviour means that the output +from tests that are run with and without \fB-s\fP should be identical, except +when options that output information about the actual running of a match are +set. +.sp +The \fB-M\fP, \fB-t\fP, and \fB-tm\fP options, which give information about +resources used, are likely to produce different output with and without +\fB-s\fP. Output may also differ if the \fB/C\fP option is present on an +individual pattern. This uses callouts to trace the the matching process, and +this may be different between studied and non-studied patterns. If the pattern +contains (*MARK) items there may also be differences, for the same reason. The +\fB-s\fP command line option can be overridden for specific patterns that +should never be studied (see the \fB/S\fP pattern modifier below). +.TP 10 +\fB-t\fP +Run each compile, study, and match many times with a timer, and output the +resulting times per compile, study, or match (in milliseconds). Do not set +\fB-m\fP with \fB-t\fP, because you will then get the size output a zillion +times, and the timing will be distorted. You can control the number of +iterations that are used for timing by following \fB-t\fP with a number (as a +separate item on the command line). For example, "-t 1000" iterates 1000 times. +The default is to iterate 500000 times. +.TP 10 +\fB-tm\fP +This is like \fB-t\fP except that it times only the matching phase, not the +compile or study phases. +.TP 10 +\fB-T\fP \fB-TM\fP +These behave like \fB-t\fP and \fB-tm\fP, but in addition, at the end of a run, +the total times for all compiles, studies, and matches are output. +. +. +.SH DESCRIPTION +.rs +.sp +If \fBpcretest\fP 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. +.P +When \fBpcretest\fP is built, a configuration option can specify that it should +be linked with the \fBlibreadline\fP library. When this is done, if the input +is from a terminal, it is read using the \fBreadline()\fP function. This +provides line-editing and history facilities. The output from the \fB-help\fP +option states whether or not \fBreadline()\fP will be used. +.P +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 that pattern. +.P +Each data line is matched separately and independently. If you want to do +multi-line matches, you have to use the \en escape sequence (or \er or \er\en, +etc., depending on the newline setting) in a single line of input to encode the +newline sequences. There is no limit on the length of data lines; the input +buffer is automatically extended if it is too small. +.P +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-alphanumeric delimiters other than backslash, for example: +.sp + /(a|bc)x+yz/ +.sp +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 +.sp + /abc\e/def/ +.sp +If you do so, the escape and the delimiter form part of the pattern, but since +delimiters are always non-alphanumeric, this does not affect its interpretation. +If the terminating delimiter is immediately followed by a backslash, for +example, +.sp + /abc/\e +.sp +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 +.sp + /abc\e/ +.sp +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 +A pattern may be followed by any number of modifiers, which are mostly single +characters, though some of these can be qualified by further characters. +Following Perl usage, these are referred to below as, for example, "the +\fB/i\fP modifier", even though the delimiter of the pattern need not always be +a slash, and no slash is used when writing modifiers. White space may appear +between the final pattern delimiter and the first modifier, and between the +modifiers themselves. For reference, here is a complete list of modifiers. They +fall into several groups that are described in detail in the following +sections. +.sp + \fB/8\fP set UTF mode + \fB/9\fP set PCRE_NEVER_UTF (locks out UTF mode) + \fB/?\fP disable UTF validity check + \fB/+\fP show remainder of subject after match + \fB/=\fP show all captures (not just those that are set) +.sp + \fB/A\fP set PCRE_ANCHORED + \fB/B\fP show compiled code + \fB/C\fP set PCRE_AUTO_CALLOUT + \fB/D\fP same as \fB/B\fP plus \fB/I\fP + \fB/E\fP set PCRE_DOLLAR_ENDONLY + \fB/F\fP flip byte order in compiled pattern + \fB/f\fP set PCRE_FIRSTLINE + \fB/G\fP find all matches (shorten string) + \fB/g\fP find all matches (use startoffset) + \fB/I\fP show information about pattern + \fB/i\fP set PCRE_CASELESS + \fB/J\fP set PCRE_DUPNAMES + \fB/K\fP show backtracking control names + \fB/L\fP set locale + \fB/M\fP show compiled memory size + \fB/m\fP set PCRE_MULTILINE + \fB/N\fP set PCRE_NO_AUTO_CAPTURE + \fB/O\fP set PCRE_NO_AUTO_POSSESS + \fB/P\fP use the POSIX wrapper + \fB/Q\fP test external stack check function + \fB/S\fP study the pattern after compilation + \fB/s\fP set PCRE_DOTALL + \fB/T\fP select character tables + \fB/U\fP set PCRE_UNGREEDY + \fB/W\fP set PCRE_UCP + \fB/X\fP set PCRE_EXTRA + \fB/x\fP set PCRE_EXTENDED + \fB/Y\fP set PCRE_NO_START_OPTIMIZE + \fB/Z\fP don't show lengths in \fB/B\fP output +.sp + \fB/<any>\fP set PCRE_NEWLINE_ANY + \fB/<anycrlf>\fP set PCRE_NEWLINE_ANYCRLF + \fB/<cr>\fP set PCRE_NEWLINE_CR + \fB/<crlf>\fP set PCRE_NEWLINE_CRLF + \fB/<lf>\fP set PCRE_NEWLINE_LF + \fB/<bsr_anycrlf>\fP set PCRE_BSR_ANYCRLF + \fB/<bsr_unicode>\fP set PCRE_BSR_UNICODE + \fB/<JS>\fP set PCRE_JAVASCRIPT_COMPAT +.sp +. +. +.SS "Perl-compatible modifiers" +.rs +.sp +The \fB/i\fP, \fB/m\fP, \fB/s\fP, and \fB/x\fP modifiers set the PCRE_CASELESS, +PCRE_MULTILINE, PCRE_DOTALL, or PCRE_EXTENDED options, respectively, when +\fBpcre[16|32]_compile()\fP is called. These four modifier letters have the same +effect as they do in Perl. For example: +.sp + /caseless/i +.sp +. +. +.SS "Modifiers for other PCRE options" +.rs +.sp +The following table shows additional modifiers for setting PCRE compile-time +options that do not correspond to anything in Perl: +.sp + \fB/8\fP PCRE_UTF8 ) when using the 8-bit + \fB/?\fP PCRE_NO_UTF8_CHECK ) library +.sp + \fB/8\fP PCRE_UTF16 ) when using the 16-bit + \fB/?\fP PCRE_NO_UTF16_CHECK ) library +.sp + \fB/8\fP PCRE_UTF32 ) when using the 32-bit + \fB/?\fP PCRE_NO_UTF32_CHECK ) library +.sp + \fB/9\fP PCRE_NEVER_UTF + \fB/A\fP PCRE_ANCHORED + \fB/C\fP PCRE_AUTO_CALLOUT + \fB/E\fP PCRE_DOLLAR_ENDONLY + \fB/f\fP PCRE_FIRSTLINE + \fB/J\fP PCRE_DUPNAMES + \fB/N\fP PCRE_NO_AUTO_CAPTURE + \fB/O\fP PCRE_NO_AUTO_POSSESS + \fB/U\fP PCRE_UNGREEDY + \fB/W\fP PCRE_UCP + \fB/X\fP PCRE_EXTRA + \fB/Y\fP PCRE_NO_START_OPTIMIZE + \fB/<any>\fP PCRE_NEWLINE_ANY + \fB/<anycrlf>\fP PCRE_NEWLINE_ANYCRLF + \fB/<cr>\fP PCRE_NEWLINE_CR + \fB/<crlf>\fP PCRE_NEWLINE_CRLF + \fB/<lf>\fP PCRE_NEWLINE_LF + \fB/<bsr_anycrlf>\fP PCRE_BSR_ANYCRLF + \fB/<bsr_unicode>\fP PCRE_BSR_UNICODE + \fB/<JS>\fP PCRE_JAVASCRIPT_COMPAT +.sp +The modifiers that are enclosed in angle brackets are literal strings as shown, +including the angle brackets, but the letters within can be in either case. +This example sets multiline matching with CRLF as the line ending sequence: +.sp + /^abc/m<CRLF> +.sp +As well as turning on the PCRE_UTF8/16/32 option, the \fB/8\fP modifier causes +all non-printing characters in output strings to be printed using the +\ex{hh...} notation. Otherwise, those less than 0x100 are output in hex without +the curly brackets. +.P +Full details of the PCRE options are given in the +.\" HREF +\fBpcreapi\fP +.\" +documentation. +. +. +.SS "Finding all matches in a string" +.rs +.sp +Searching for all possible matches within each subject string can be requested +by the \fB/g\fP or \fB/G\fP modifier. After finding a match, PCRE is called +again to search the remainder of the subject string. The difference between +\fB/g\fP and \fB/G\fP is that the former uses the \fIstartoffset\fP argument to +\fBpcre[16|32]_exec()\fP 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 \eb or \eB). +.P +If any call to \fBpcre[16|32]_exec()\fP in a \fB/g\fP or \fB/G\fP sequence matches +an empty string, the next call is done with the PCRE_NOTEMPTY_ATSTART 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, and the +normal match is retried. This imitates the way Perl handles such cases when +using the \fB/g\fP modifier or the \fBsplit()\fP function. Normally, the start +offset is advanced by one character, but if the newline convention recognizes +CRLF as a newline, and the current character is CR followed by LF, an advance +of two is used. +. +. +.SS "Other modifiers" +.rs +.sp +There are yet more modifiers for controlling the way \fBpcretest\fP +operates. +.P +The \fB/+\fP modifier requests that as well as outputting the substring that +matched the entire pattern, \fBpcretest\fP 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. If the \fB+\fP modifier appears +twice, the same action is taken for captured substrings. In each case the +remainder is output on the following line with a plus character following the +capture number. Note that this modifier must not immediately follow the /S +modifier because /S+ and /S++ have other meanings. +.P +The \fB/=\fP modifier requests that the values of all potential captured +parentheses be output after a match. By default, only those up to the highest +one actually used in the match are output (corresponding to the return code +from \fBpcre[16|32]_exec()\fP). Values in the offsets vector corresponding to +higher numbers should be set to -1, and these are output as "<unset>". This +modifier gives a way of checking that this is happening. +.P +The \fB/B\fP modifier is a debugging feature. It requests that \fBpcretest\fP +output a representation of the compiled code after compilation. Normally this +information contains length and offset values; however, if \fB/Z\fP is also +present, this data is replaced by spaces. This is a special feature for use in +the automatic test scripts; it ensures that the same output is generated for +different internal link sizes. +.P +The \fB/D\fP modifier is a PCRE debugging feature, and is equivalent to +\fB/BI\fP, that is, both the \fB/B\fP and the \fB/I\fP modifiers. +.P +The \fB/F\fP modifier causes \fBpcretest\fP to flip the byte order of the +2-byte and 4-byte fields in the compiled pattern. This facility is for testing +the feature in PCRE that allows it to execute patterns that were compiled on a +host with a different endianness. This feature is not available when the POSIX +interface to PCRE is being used, that is, when the \fB/P\fP pattern modifier is +specified. See also the section about saving and reloading compiled patterns +below. +.P +The \fB/I\fP modifier requests that \fBpcretest\fP output information about the +compiled pattern (whether it is anchored, has a fixed first character, and +so on). It does this by calling \fBpcre[16|32]_fullinfo()\fP after compiling a +pattern. If the pattern is studied, the results of that are also output. In +this output, the word "char" means a non-UTF character, that is, the value of a +single data item (8-bit, 16-bit, or 32-bit, depending on the library that is +being tested). +.P +The \fB/K\fP modifier requests \fBpcretest\fP to show names from backtracking +control verbs that are returned from calls to \fBpcre[16|32]_exec()\fP. It causes +\fBpcretest\fP to create a \fBpcre[16|32]_extra\fP block if one has not already +been created by a call to \fBpcre[16|32]_study()\fP, and to set the +PCRE_EXTRA_MARK flag and the \fBmark\fP field within it, every time that +\fBpcre[16|32]_exec()\fP is called. If the variable that the \fBmark\fP field +points to is non-NULL for a match, non-match, or partial match, \fBpcretest\fP +prints the string to which it points. For a match, this is shown on a line by +itself, tagged with "MK:". For a non-match it is added to the message. +.P +The \fB/L\fP modifier must be followed directly by the name of a locale, for +example, +.sp + /pattern/Lfr_FR +.sp +For this reason, it must be the last modifier. The given locale is set, +\fBpcre[16|32]_maketables()\fP is called to build a set of character tables for +the locale, and this is then passed to \fBpcre[16|32]_compile()\fP when compiling +the regular expression. Without an \fB/L\fP (or \fB/T\fP) modifier, NULL is +passed as the tables pointer; that is, \fB/L\fP applies only to the expression +on which it appears. +.P +The \fB/M\fP modifier causes the size in bytes of the memory block used to hold +the compiled pattern to be output. This does not include the size of the +\fBpcre[16|32]\fP block; it is just the actual compiled data. If the pattern is +successfully studied with the PCRE_STUDY_JIT_COMPILE option, the size of the +JIT compiled code is also output. +.P +The \fB/Q\fP modifier is used to test the use of \fBpcre_stack_guard\fP. It +must be followed by '0' or '1', specifying the return code to be given from an +external function that is passed to PCRE and used for stack checking during +compilation (see the +.\" HREF +\fBpcreapi\fP +.\" +documentation for details). +.P +The \fB/S\fP modifier causes \fBpcre[16|32]_study()\fP to be called after the +expression has been compiled, and the results used when the expression is +matched. There are a number of qualifying characters that may follow \fB/S\fP. +They may appear in any order. +.P +If \fB/S\fP is followed by an exclamation mark, \fBpcre[16|32]_study()\fP is +called with the PCRE_STUDY_EXTRA_NEEDED option, causing it always to return a +\fBpcre_extra\fP block, even when studying discovers no useful information. +.P +If \fB/S\fP is followed by a second S character, it suppresses studying, even +if it was requested externally by the \fB-s\fP command line option. This makes +it possible to specify that certain patterns are always studied, and others are +never studied, independently of \fB-s\fP. This feature is used in the test +files in a few cases where the output is different when the pattern is studied. +.P +If the \fB/S\fP modifier is followed by a + character, the call to +\fBpcre[16|32]_study()\fP is made with all the JIT study options, requesting +just-in-time optimization support if it is available, for both normal and +partial matching. If you want to restrict the JIT compiling modes, you can +follow \fB/S+\fP with a digit in the range 1 to 7: +.sp + 1 normal match only + 2 soft partial match only + 3 normal match and soft partial match + 4 hard partial match only + 6 soft and hard partial match + 7 all three modes (default) +.sp +If \fB/S++\fP is used instead of \fB/S+\fP (with or without a following digit), +the text "(JIT)" is added to the first output line after a match or no match +when JIT-compiled code was actually used. +.P +Note that there is also an independent \fB/+\fP modifier; it must not be given +immediately after \fB/S\fP or \fB/S+\fP because this will be misinterpreted. +.P +If JIT studying is successful, the compiled JIT code will automatically be used +when \fBpcre[16|32]_exec()\fP is run, except when incompatible run-time options +are specified. For more details, see the +.\" HREF +\fBpcrejit\fP +.\" +documentation. See also the \fB\eJ\fP escape sequence below for a way of +setting the size of the JIT stack. +.P +Finally, if \fB/S\fP is followed by a minus character, JIT compilation is +suppressed, even if it was requested externally by the \fB-s\fP command line +option. This makes it possible to specify that JIT is never to be used for +certain patterns. +.P +The \fB/T\fP modifier must be followed by a single digit. It causes a specific +set of built-in character tables to be passed to \fBpcre[16|32]_compile()\fP. It +is used in the standard PCRE tests to check behaviour with different character +tables. The digit specifies the tables as follows: +.sp + 0 the default ASCII tables, as distributed in + pcre_chartables.c.dist + 1 a set of tables defining ISO 8859 characters +.sp +In table 1, some characters whose codes are greater than 128 are identified as +letters, digits, spaces, etc. +. +. +.SS "Using the POSIX wrapper API" +.rs +.sp +The \fB/P\fP modifier causes \fBpcretest\fP to call PCRE via the POSIX wrapper +API rather than its native API. This supports only the 8-bit library. When +\fB/P\fP is set, the following modifiers set options for the \fBregcomp()\fP +function: +.sp + /i REG_ICASE + /m REG_NEWLINE + /N REG_NOSUB + /s REG_DOTALL ) + /U REG_UNGREEDY ) These options are not part of + /W REG_UCP ) the POSIX standard + /8 REG_UTF8 ) +.sp +The \fB/+\fP modifier works as described above. All other modifiers are +ignored. +. +. +.SS "Locking out certain modifiers" +.rs +.sp +PCRE can be compiled with or without support for certain features such as +UTF-8/16/32 or Unicode properties. Accordingly, the standard tests are split up +into a number of different files that are selected for running depending on +which features are available. When updating the tests, it is all too easy to +put a new test into the wrong file by mistake; for example, to put a test that +requires UTF support into a file that is used when it is not available. To help +detect such mistakes as early as possible, there is a facility for locking out +specific modifiers. If an input line for \fBpcretest\fP starts with the string +"< forbid " the following sequence of characters is taken as a list of +forbidden modifiers. For example, in the test files that must not use UTF or +Unicode property support, this line appears: +.sp + < forbid 8W +.sp +This locks out the /8 and /W modifiers. An immediate error is given if they are +subsequently encountered. If the character string contains < but not >, all the +multi-character modifiers that begin with < are locked out. Otherwise, such +modifiers must be explicitly listed, for example: +.sp + < forbid <JS><cr> +.sp +There must be a single space between < and "forbid" for this feature to be +recognised. If there is not, the line is interpreted either as a request to +re-load a pre-compiled pattern (see "SAVING AND RELOADING COMPILED PATTERNS" +below) or, if there is a another < character, as a pattern that uses < as its +delimiter. +. +. +.SH "DATA LINES" +.rs +.sp +Before each data line is passed to \fBpcre[16|32]_exec()\fP, leading and trailing +white space is removed, and it is then scanned for \e 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: +.sp + \ea alarm (BEL, \ex07) + \eb backspace (\ex08) + \ee escape (\ex27) + \ef form feed (\ex0c) + \en newline (\ex0a) +.\" JOIN + \eqdd set the PCRE_MATCH_LIMIT limit to dd + (any number of digits) + \er carriage return (\ex0d) + \et tab (\ex09) + \ev vertical tab (\ex0b) + \ennn octal character (up to 3 octal digits); always + a byte unless > 255 in UTF-8 or 16-bit or 32-bit mode + \eo{dd...} octal character (any number of octal digits} + \exhh hexadecimal byte (up to 2 hex digits) + \ex{hh...} hexadecimal character (any number of hex digits) +.\" JOIN + \eA pass the PCRE_ANCHORED option to \fBpcre[16|32]_exec()\fP + or \fBpcre[16|32]_dfa_exec()\fP +.\" JOIN + \eB pass the PCRE_NOTBOL option to \fBpcre[16|32]_exec()\fP + or \fBpcre[16|32]_dfa_exec()\fP +.\" JOIN + \eCdd call pcre[16|32]_copy_substring() for substring dd + after a successful match (number less than 32) +.\" JOIN + \eCname call pcre[16|32]_copy_named_substring() for substring + "name" after a successful match (name termin- + ated by next non alphanumeric character) +.\" JOIN + \eC+ show the current captured substrings at callout + time + \eC- do not supply a callout function +.\" JOIN + \eC!n return 1 instead of 0 when callout number n is + reached +.\" JOIN + \eC!n!m return 1 instead of 0 when callout number n is + reached for the nth time +.\" JOIN + \eC*n pass the number n (may be negative) as callout + data; this is used as the callout return value + \eD use the \fBpcre[16|32]_dfa_exec()\fP match function + \eF only shortest match for \fBpcre[16|32]_dfa_exec()\fP +.\" JOIN + \eGdd call pcre[16|32]_get_substring() for substring dd + after a successful match (number less than 32) +.\" JOIN + \eGname call pcre[16|32]_get_named_substring() for substring + "name" after a successful match (name termin- + ated by next non-alphanumeric character) +.\" JOIN + \eJdd set up a JIT stack of dd kilobytes maximum (any + number of digits) +.\" JOIN + \eL call pcre[16|32]_get_substringlist() after a + successful match +.\" JOIN + \eM discover the minimum MATCH_LIMIT and + MATCH_LIMIT_RECURSION settings +.\" JOIN + \eN pass the PCRE_NOTEMPTY option to \fBpcre[16|32]_exec()\fP + or \fBpcre[16|32]_dfa_exec()\fP; if used twice, pass the + PCRE_NOTEMPTY_ATSTART option +.\" JOIN + \eOdd set the size of the output vector passed to + \fBpcre[16|32]_exec()\fP to dd (any number of digits) +.\" JOIN + \eP pass the PCRE_PARTIAL_SOFT option to \fBpcre[16|32]_exec()\fP + or \fBpcre[16|32]_dfa_exec()\fP; if used twice, pass the + PCRE_PARTIAL_HARD option +.\" JOIN + \eQdd set the PCRE_MATCH_LIMIT_RECURSION limit to dd + (any number of digits) + \eR pass the PCRE_DFA_RESTART option to \fBpcre[16|32]_dfa_exec()\fP + \eS output details of memory get/free calls during matching +.\" JOIN + \eY pass the PCRE_NO_START_OPTIMIZE option to \fBpcre[16|32]_exec()\fP + or \fBpcre[16|32]_dfa_exec()\fP +.\" JOIN + \eZ pass the PCRE_NOTEOL option to \fBpcre[16|32]_exec()\fP + or \fBpcre[16|32]_dfa_exec()\fP +.\" JOIN + \e? pass the PCRE_NO_UTF[8|16|32]_CHECK option to + \fBpcre[16|32]_exec()\fP or \fBpcre[16|32]_dfa_exec()\fP +.\" JOIN + \e>dd start the match at offset dd (optional "-"; then + any number of digits); this sets the \fIstartoffset\fP + argument for \fBpcre[16|32]_exec()\fP or \fBpcre[16|32]_dfa_exec()\fP +.\" JOIN + \e<cr> pass the PCRE_NEWLINE_CR option to \fBpcre[16|32]_exec()\fP + or \fBpcre[16|32]_dfa_exec()\fP +.\" JOIN + \e<lf> pass the PCRE_NEWLINE_LF option to \fBpcre[16|32]_exec()\fP + or \fBpcre[16|32]_dfa_exec()\fP +.\" JOIN + \e<crlf> pass the PCRE_NEWLINE_CRLF option to \fBpcre[16|32]_exec()\fP + or \fBpcre[16|32]_dfa_exec()\fP +.\" JOIN + \e<anycrlf> pass the PCRE_NEWLINE_ANYCRLF option to \fBpcre[16|32]_exec()\fP + or \fBpcre[16|32]_dfa_exec()\fP +.\" JOIN + \e<any> pass the PCRE_NEWLINE_ANY option to \fBpcre[16|32]_exec()\fP + or \fBpcre[16|32]_dfa_exec()\fP +.sp +The use of \ex{hh...} is not dependent on the use of the \fB/8\fP modifier on +the pattern. It is recognized always. There may be any number of hexadecimal +digits inside the braces; invalid values provoke error messages. +.P +Note that \exhh specifies one byte rather than one character in UTF-8 mode; +this makes it possible to construct invalid UTF-8 sequences for testing +purposes. On the other hand, \ex{hh} is interpreted as a UTF-8 character in +UTF-8 mode, generating more than one byte if the value is greater than 127. +When testing the 8-bit library not in UTF-8 mode, \ex{hh} generates one byte +for values less than 256, and causes an error for greater values. +.P +In UTF-16 mode, all 4-digit \ex{hhhh} values are accepted. This makes it +possible to construct invalid UTF-16 sequences for testing purposes. +.P +In UTF-32 mode, all 4- to 8-digit \ex{...} values are accepted. This makes it +possible to construct invalid UTF-32 sequences for testing purposes. +.P +The escapes that specify line ending sequences are literal strings, exactly as +shown. No more than one newline setting should be present in any data line. +.P +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. +.P +The \fB\eJ\fP escape provides a way of setting the maximum stack size that is +used by the just-in-time optimization code. It is ignored if JIT optimization +is not being used. Providing a stack that is larger than the default 32K is +necessary only for very complicated patterns. +.P +If \eM is present, \fBpcretest\fP calls \fBpcre[16|32]_exec()\fP several times, +with different values in the \fImatch_limit\fP and \fImatch_limit_recursion\fP +fields of the \fBpcre[16|32]_extra\fP data structure, until it finds the minimum +numbers for each parameter that allow \fBpcre[16|32]_exec()\fP to complete without +error. Because this is testing a specific feature of the normal interpretive +\fBpcre[16|32]_exec()\fP execution, the use of any JIT optimization that might +have been set up by the \fB/S+\fP qualifier of \fB-s+\fP option is disabled. +.P +The \fImatch_limit\fP number is a measure of the amount of 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. The \fImatch_limit_recursion\fP number is a measure of how +much stack (or, if PCRE is compiled with NO_RECURSE, how much heap) memory is +needed to complete the match attempt. +.P +When \eO is used, the value specified may be higher or lower than the size set +by the \fB-O\fP command line option (or defaulted to 45); \eO applies only to +the call of \fBpcre[16|32]_exec()\fP for the line in which it appears. +.P +If the \fB/P\fP modifier was present on the pattern, causing the POSIX wrapper +API to be used, the only option-setting sequences that have any effect are \eB, +\eN, and \eZ, causing REG_NOTBOL, REG_NOTEMPTY, and REG_NOTEOL, respectively, +to be passed to \fBregexec()\fP. +. +. +.SH "THE ALTERNATIVE MATCHING FUNCTION" +.rs +.sp +By default, \fBpcretest\fP uses the standard PCRE matching function, +\fBpcre[16|32]_exec()\fP to match each data line. PCRE also supports an +alternative matching function, \fBpcre[16|32]_dfa_test()\fP, which operates in a +different way, and has some restrictions. The differences between the two +functions are described in the +.\" HREF +\fBpcrematching\fP +.\" +documentation. +.P +If a data line contains the \eD escape sequence, or if the command line +contains the \fB-dfa\fP option, the alternative matching function is used. +This function finds all possible matches at a given point. If, however, the \eF +escape sequence is present in the data line, it stops after the first match is +found. This is always the shortest possible match. +. +. +.SH "DEFAULT OUTPUT FROM PCRETEST" +.rs +.sp +This section describes the output when the normal matching function, +\fBpcre[16|32]_exec()\fP, is being used. +.P +When a match succeeds, \fBpcretest\fP outputs the list of captured substrings +that \fBpcre[16|32]_exec()\fP returns, starting with number 0 for the string that +matched the whole pattern. Otherwise, it outputs "No match" when the return is +PCRE_ERROR_NOMATCH, and "Partial match:" followed by the partially matching +substring when \fBpcre[16|32]_exec()\fP returns PCRE_ERROR_PARTIAL. (Note that +this is the entire substring that was inspected during the partial match; it +may include characters before the actual match start if a lookbehind assertion, +\eK, \eb, or \eB was involved.) For any other return, \fBpcretest\fP outputs +the PCRE negative error number and a short descriptive phrase. If the error is +a failed UTF string check, the offset of the start of the failing character and +the reason code are also output, provided that the size of the output vector is +at least two. Here is an example of an interactive \fBpcretest\fP run. +.sp + $ pcretest + PCRE version 8.13 2011-04-30 +.sp + re> /^abc(\ed+)/ + data> abc123 + 0: abc123 + 1: 123 + data> xyz + No match +.sp +Unset capturing substrings that are not followed by one that is set are not +returned by \fBpcre[16|32]_exec()\fP, and are not shown by \fBpcretest\fP. In the +following example, there are two capturing substrings, but when the first data +line is matched, the second, unset substring is not shown. An "internal" unset +substring is shown as "<unset>", as for the second data line. +.sp + re> /(a)|(b)/ + data> a + 0: a + 1: a + data> b + 0: b + 1: <unset> + 2: b +.sp +If the strings contain any non-printing characters, they are output as \exhh +escapes if the value is less than 256 and UTF mode is not set. Otherwise they +are output as \ex{hh...} escapes. See below for the definition of non-printing +characters. If the pattern has the \fB/+\fP modifier, the output for substring +0 is followed by the the rest of the subject string, identified by "0+" like +this: +.sp + re> /cat/+ + data> cataract + 0: cat + 0+ aract +.sp +If the pattern has the \fB/g\fP or \fB/G\fP modifier, the results of successive +matching attempts are output in sequence, like this: +.sp + re> /\eBi(\ew\ew)/g + data> Mississippi + 0: iss + 1: ss + 0: iss + 1: ss + 0: ipp + 1: pp +.sp +"No match" is output only if the first match attempt fails. Here is an example +of a failure message (the offset 4 that is specified by \e>4 is past the end of +the subject string): +.sp + re> /xyz/ + data> xyz\e>4 + Error -24 (bad offset value) +.P +If any of the sequences \fB\eC\fP, \fB\eG\fP, or \fB\eL\fP 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\eC\fP and \fB\eG\fP. +.P +Note that whereas 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 \en escape (or \er, \er\en, etc., depending on +the newline sequence setting). +. +. +. +.SH "OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION" +.rs +.sp +When the alternative matching function, \fBpcre[16|32]_dfa_exec()\fP, is used (by +means of the \eD escape sequence or the \fB-dfa\fP command line option), the +output consists of a list of all the matches that start at the first point in +the subject where there is at least one match. For example: +.sp + re> /(tang|tangerine|tan)/ + data> yellow tangerine\eD + 0: tangerine + 1: tang + 2: tan +.sp +(Using the normal matching function on this data finds only "tang".) The +longest matching string is always given first (and numbered zero). After a +PCRE_ERROR_PARTIAL return, the output is "Partial match:", followed by the +partially matching substring. (Note that this is the entire substring that was +inspected during the partial match; it may include characters before the actual +match start if a lookbehind assertion, \eK, \eb, or \eB was involved.) +.P +If \fB/g\fP is present on the pattern, the search for further matches resumes +at the end of the longest match. For example: +.sp + re> /(tang|tangerine|tan)/g + data> yellow tangerine and tangy sultana\eD + 0: tangerine + 1: tang + 2: tan + 0: tang + 1: tan + 0: tan +.sp +Since the matching function does not support substring capture, the escape +sequences that are concerned with captured substrings are not relevant. +. +. +.SH "RESTARTING AFTER A PARTIAL MATCH" +.rs +.sp +When the alternative matching function has given the PCRE_ERROR_PARTIAL return, +indicating that the subject partially matched the pattern, you can restart the +match with additional subject data by means of the \eR escape sequence. For +example: +.sp + re> /^\ed?\ed(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\ed\ed$/ + data> 23ja\eP\eD + Partial match: 23ja + data> n05\eR\eD + 0: n05 +.sp +For further information about partial matching, see the +.\" HREF +\fBpcrepartial\fP +.\" +documentation. +. +. +.SH CALLOUTS +.rs +.sp +If the pattern contains any callout requests, \fBpcretest\fP's callout function +is called during matching. This works with both matching functions. By default, +the called function displays the callout number, the start and current +positions in the text at the callout time, and the next pattern item to be +tested. For example: +.sp + --->pqrabcdef + 0 ^ ^ \ed +.sp +This output 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 of the data, and when the next pattern item was \ed. Just +one circumflex is output if the start and current positions are the same. +.P +Callouts numbered 255 are assumed to be automatic callouts, inserted as a +result of the \fB/C\fP pattern modifier. In this case, instead of showing the +callout number, the offset in the pattern, preceded by a plus, is output. For +example: +.sp + re> /\ed?[A-E]\e*/C + data> E* + --->E* + +0 ^ \ed? + +3 ^ [A-E] + +8 ^^ \e* + +10 ^ ^ + 0: E* +.sp +If a pattern contains (*MARK) items, an additional line is output whenever +a change of latest mark is passed to the callout function. For example: +.sp + re> /a(*MARK:X)bc/C + data> abc + --->abc + +0 ^ a + +1 ^^ (*MARK:X) + +10 ^^ b + Latest Mark: X + +11 ^ ^ c + +12 ^ ^ + 0: abc +.sp +The mark changes between matching "a" and "b", but stays the same for the rest +of the match, so nothing more is output. If, as a result of backtracking, the +mark reverts to being unset, the text "<unset>" is output. +.P +The callout function in \fBpcretest\fP returns zero (carry on matching) by +default, but you can use a \eC item in a data line (as described above) to +change this and other parameters of the callout. +.P +Inserting callouts can be helpful when using \fBpcretest\fP to check +complicated regular expressions. For further information about callouts, see +the +.\" HREF +\fBpcrecallout\fP +.\" +documentation. +. +. +. +.SH "NON-PRINTING CHARACTERS" +.rs +.sp +When \fBpcretest\fP is outputting text in the compiled version of a pattern, +bytes other than 32-126 are always treated as non-printing characters are are +therefore shown as hex escapes. +.P +When \fBpcretest\fP is outputting text that is a matched part of a subject +string, it behaves in the same way, unless a different locale has been set for +the pattern (using the \fB/L\fP modifier). In this case, the \fBisprint()\fP +function to distinguish printing and non-printing characters. +. +. +. +.SH "SAVING AND RELOADING COMPILED PATTERNS" +.rs +.sp +The facilities described in this section are not available when the POSIX +interface to PCRE is being used, that is, when the \fB/P\fP pattern modifier is +specified. +.P +When the POSIX interface is not in use, you can cause \fBpcretest\fP to write a +compiled pattern to a file, by following the modifiers with > and a file name. +For example: +.sp + /pattern/im >/some/file +.sp +See the +.\" HREF +\fBpcreprecompile\fP +.\" +documentation for a discussion about saving and re-using compiled patterns. +Note that if the pattern was successfully studied with JIT optimization, the +JIT data cannot be saved. +.P +The data that is written is binary. The first eight bytes are the length of the +compiled pattern data followed by the length of the optional study data, each +written as four bytes in big-endian order (most significant byte first). If +there is no study data (either the pattern was not studied, or studying did not +return any data), the second length is zero. The lengths are followed by an +exact copy of the compiled pattern. If there is additional study data, this +(excluding any JIT data) follows immediately after the compiled pattern. After +writing the file, \fBpcretest\fP expects to read a new pattern. +.P +A saved pattern can be reloaded into \fBpcretest\fP by specifying < and a file +name instead of a pattern. There must be no space between < and the file name, +which must not contain a < character, as otherwise \fBpcretest\fP will +interpret the line as a pattern delimited by < characters. For example: +.sp + re> </some/file + Compiled pattern loaded from /some/file + No study data +.sp +If the pattern was previously studied with the JIT optimization, the JIT +information cannot be saved and restored, and so is lost. When the pattern has +been loaded, \fBpcretest\fP proceeds to read data lines in the usual way. +.P +You can copy a file written by \fBpcretest\fP to a different host and reload it +there, even if the new host has opposite endianness to the one on which the +pattern was compiled. For example, you can compile on an i86 machine and run on +a SPARC machine. When a pattern is reloaded on a host with different +endianness, the confirmation message is changed to: +.sp + Compiled pattern (byte-inverted) loaded from /some/file +.sp +The test suite contains some saved pre-compiled patterns with different +endianness. These are reloaded using "<!" instead of just "<". This suppresses +the "(byte-inverted)" text so that the output is the same on all hosts. It also +forces debugging output once the pattern has been reloaded. +.P +File names for saving and reloading can be absolute or relative, but note that +the shell facility of expanding a file name that starts with a tilde (~) is not +available. +.P +The ability to save and reload files in \fBpcretest\fP is intended for testing +and experimentation. It is not intended for production use because only a +single pattern can be written to a file. Furthermore, there is no facility for +supplying custom character tables for use with a reloaded pattern. If the +original pattern was compiled with custom tables, an attempt to match a subject +string using a reloaded pattern is likely to cause \fBpcretest\fP to crash. +Finally, if you attempt to load a file that is not in the correct format, the +result is undefined. +. +. +.SH "SEE ALSO" +.rs +.sp +\fBpcre\fP(3), \fBpcre16\fP(3), \fBpcre32\fP(3), \fBpcreapi\fP(3), +\fBpcrecallout\fP(3), +\fBpcrejit\fP, \fBpcrematching\fP(3), \fBpcrepartial\fP(d), +\fBpcrepattern\fP(3), \fBpcreprecompile\fP(3). +. +. +.SH AUTHOR +.rs +.sp +.nf +Philip Hazel +University Computing Service +Cambridge CB2 3QH, England. +.fi +. +. +.SH REVISION +.rs +.sp +.nf +Last updated: 09 February 2014 +Copyright (c) 1997-2014 University of Cambridge. +.fi |