diff -r 000000000000 -r 7f656887cf89 libraries/spcre/libpcre/pcre/doc/pcretest.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/libraries/spcre/libpcre/pcre/doc/pcretest.1 Wed Jun 23 15:52:26 2010 +0100 @@ -0,0 +1,723 @@ +.TH PCRETEST 1 +.SH NAME +pcretest - a program for testing Perl-compatible regular expressions. +.SH SYNOPSIS +.rs +.sp +.B pcretest "[options] [source] [destination]" +.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 +.\" +documentation. +. +. +.SH OPTIONS +.rs +.TP 10 +\fB-b\fP +Behave as if each regex has the \fB/B\fP (show bytecode) 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. +.TP 10 +\fB-d\fP +Behave as if each regex 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_dfa_exec()\fP, to be used instead of the +standard \fBpcre_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 regex has the \fB/I\fP modifier; information about the +compiled pattern is given after compilation. +.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. For compatibility +with earlier versions of pcretest, \fB-s\fP is a synonym for \fB-m\fP. +.TP 10 +\fB-o\fP \fIosize\fP +Set the number of elements in the output vector that is used when calling +\fBpcre_exec()\fP or \fBpcre_dfa_exec()\fP to be \fIosize\fP. The default value +is 45, which is enough for 14 capturing subexpressions for \fBpcre_exec()\fP or +22 different matches for \fBpcre_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 regex 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. +.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 runtime stack to \fIsize\fP +megabytes. +.TP 10 +\fB-t\fP +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-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" would iterate 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. +. +. +.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 the 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. 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. Whitespace may +appear between the final pattern delimiter and the first modifier, and between +the modifiers themselves. +.P +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_compile()\fP is called. These four modifier letters have the same +effect as they do in Perl. For example: +.sp + /caseless/i +.sp +The following table shows additional modifiers for setting PCRE options that do +not correspond to anything in Perl: +.sp + \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/U\fP PCRE_UNGREEDY + \fB/X\fP PCRE_EXTRA + \fB/\fP PCRE_JAVASCRIPT_COMPAT + \fB/\fP PCRE_NEWLINE_CR + \fB/\fP PCRE_NEWLINE_LF + \fB/\fP PCRE_NEWLINE_CRLF + \fB/\fP PCRE_NEWLINE_ANYCRLF + \fB/\fP PCRE_NEWLINE_ANY + \fB/\fP PCRE_BSR_ANYCRLF + \fB/\fP PCRE_BSR_UNICODE +.sp +Those specifying line ending sequences are literal strings as shown, but the +letters can be in either case. This example sets multiline matching with CRLF +as the line ending sequence: +.sp + /^abc/m +.sp +Details of the meanings of these 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_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_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 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\fP modifier or the \fBsplit()\fP function. +. +. +.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, 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. +.P +The \fB/B\fP modifier is a debugging feature. It requests that \fBpcretest\fP +output a representation of the compiled byte 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/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_maketables()\fP is called to build a set of character tables for the +locale, and this is then passed to \fBpcre_compile()\fP when compiling the +regular expression. Without an \fB/L\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/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_fullinfo()\fP after compiling a +pattern. If the pattern is studied, the results of that are also output. +.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 +fields in the compiled pattern that contain 2-byte and 4-byte numbers. 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/S\fP modifier causes \fBpcre_study()\fP to be called after the +expression has been compiled, and the results used when the expression is +matched. +.P +The \fB/M\fP modifier causes the size of memory block used to hold the compiled +pattern to be output. +.P +The \fB/P\fP modifier causes \fBpcretest\fP to call PCRE via the POSIX wrapper +API rather than its native API. When this is done, all other modifiers except +\fB/i\fP, \fB/m\fP, and \fB/+\fP are ignored. REG_ICASE is set if \fB/i\fP is +present, and REG_NEWLINE is set if \fB/m\fP is present. The wrapper functions +force PCRE_DOLLAR_ENDONLY always, and PCRE_DOTALL unless REG_NEWLINE is set. +.P +The \fB/8\fP modifier causes \fBpcretest\fP 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 +\ex{hh...} notation if they are valid UTF-8 sequences. +.P +If the \fB/?\fP modifier is used with \fB/8\fP, it causes \fBpcretest\fP to +call \fBpcre_compile()\fP with the PCRE_NO_UTF8_CHECK option, to suppress the +checking of the string for UTF-8 validity. +. +. +.SH "DATA LINES" +.rs +.sp +Before each data line is passed to \fBpcre_exec()\fP, leading and trailing +whitespace 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 formfeed (\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) + \exhh hexadecimal character (up to 2 hex digits) +.\" JOIN + \ex{hh...} hexadecimal character, any number of digits + in UTF-8 mode +.\" JOIN + \eA pass the PCRE_ANCHORED option to \fBpcre_exec()\fP + or \fBpcre_dfa_exec()\fP +.\" JOIN + \eB pass the PCRE_NOTBOL option to \fBpcre_exec()\fP + or \fBpcre_dfa_exec()\fP +.\" JOIN + \eCdd call pcre_copy_substring() for substring dd + after a successful match (number less than 32) +.\" JOIN + \eCname call pcre_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_dfa_exec()\fP match function + \eF only shortest match for \fBpcre_dfa_exec()\fP +.\" JOIN + \eGdd call pcre_get_substring() for substring dd + after a successful match (number less than 32) +.\" JOIN + \eGname call pcre_get_named_substring() for substring + "name" after a successful match (name termin- + ated by next non-alphanumeric character) +.\" JOIN + \eL call pcre_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_exec()\fP + or \fBpcre_dfa_exec()\fP +.\" JOIN + \eOdd set the size of the output vector passed to + \fBpcre_exec()\fP to dd (any number of digits) +.\" JOIN + \eP pass the PCRE_PARTIAL option to \fBpcre_exec()\fP + or \fBpcre_dfa_exec()\fP +.\" JOIN + \eQdd set the PCRE_MATCH_LIMIT_RECURSION limit to dd + (any number of digits) + \eR pass the PCRE_DFA_RESTART option to \fBpcre_dfa_exec()\fP + \eS output details of memory get/free calls during matching +.\" JOIN + \eZ pass the PCRE_NOTEOL option to \fBpcre_exec()\fP + or \fBpcre_dfa_exec()\fP +.\" JOIN + \e? pass the PCRE_NO_UTF8_CHECK option to + \fBpcre_exec()\fP or \fBpcre_dfa_exec()\fP + \e>dd start the match at offset dd (any number of digits); +.\" JOIN + this sets the \fIstartoffset\fP argument for \fBpcre_exec()\fP + or \fBpcre_dfa_exec()\fP +.\" JOIN + \e pass the PCRE_NEWLINE_CR option to \fBpcre_exec()\fP + or \fBpcre_dfa_exec()\fP +.\" JOIN + \e pass the PCRE_NEWLINE_LF option to \fBpcre_exec()\fP + or \fBpcre_dfa_exec()\fP +.\" JOIN + \e pass the PCRE_NEWLINE_CRLF option to \fBpcre_exec()\fP + or \fBpcre_dfa_exec()\fP +.\" JOIN + \e pass the PCRE_NEWLINE_ANYCRLF option to \fBpcre_exec()\fP + or \fBpcre_dfa_exec()\fP +.\" JOIN + \e pass the PCRE_NEWLINE_ANY option to \fBpcre_exec()\fP + or \fBpcre_dfa_exec()\fP +.sp +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 +If \eM is present, \fBpcretest\fP calls \fBpcre_exec()\fP several times, with +different values in the \fImatch_limit\fP and \fImatch_limit_recursion\fP +fields of the \fBpcre_extra\fP data structure, until it finds the minimum +numbers for each parameter that allow \fBpcre_exec()\fP to complete. 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_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 +and \eZ, causing REG_NOTBOL and REG_NOTEOL, respectively, to be passed to +\fBregexec()\fP. +.P +The use of \ex{hh...} to represent UTF-8 characters 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. The result is from one to +six bytes, encoded according to the original UTF-8 rules of RFC 2279. This +allows for values in the range 0 to 0x7FFFFFFF. Note that not all of those are +valid Unicode code points, or indeed valid UTF-8 characters according to the +later rules in RFC 3629. +. +. +.SH "THE ALTERNATIVE MATCHING FUNCTION" +.rs +.sp +By default, \fBpcretest\fP uses the standard PCRE matching function, +\fBpcre_exec()\fP to match each data line. From release 6.0, PCRE supports an +alternative matching function, \fBpcre_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 called. +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_exec()\fP, is being used. +.P +When a match succeeds, pcretest outputs the list of captured substrings that +\fBpcre_exec()\fP returns, starting with number 0 for the string that matched +the whole pattern. Otherwise, it outputs "No match" or "Partial match" +when \fBpcre_exec()\fP returns PCRE_ERROR_NOMATCH or PCRE_ERROR_PARTIAL, +respectively, and otherwise the PCRE negative error number. Here is an example +of an interactive \fBpcretest\fP run. +.sp + $ pcretest + PCRE version 7.0 30-Nov-2006 +.sp + re> /^abc(\ed+)/ + data> abc123 + 0: abc123 + 1: 123 + data> xyz + No match +.sp +Note that unset capturing substrings that are not followed by one that is set +are not returned by \fBpcre_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 "", as for the second data line. +.sp + re> /(a)|(b)/ + data> a + 0: a + 1: a + data> b + 0: b + 1: + 2: b +.sp +If the strings contain any non-printing characters, they are output as \e0x +escapes, or as \ex{...} escapes if the \fB/8\fP modifier was present on the +pattern. 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. +.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_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). +.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, the output +.sp + --->pqrabcdef + 0 ^ ^ \ed +.sp +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 +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. +.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 +inteface 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. +.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 +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 specifing < and a file +name instead of a pattern. The name of the file must not contain a < character, +as otherwise \fBpcretest\fP will interpret the line as a pattern delimited by < +characters. +For example: +.sp + re>