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3 <title>pcrebuild specification</title>
5 <body bgcolor="#FFFFFF" text="#00005A" link="#0066FF" alink="#3399FF" vlink="#2222BB">
6 <h1>pcrebuild man page</h1>
8 Return to the <a href="index.html">PCRE index page</a>.
11 This page is part of the PCRE HTML documentation. It was generated automatically
12 from the original man page. If there is any nonsense in it, please consult the
13 man page, in case the conversion went wrong.
16 <li><a name="TOC1" href="#SEC1">BUILDING PCRE</a>
17 <li><a name="TOC2" href="#SEC2">PCRE BUILD-TIME OPTIONS</a>
18 <li><a name="TOC3" href="#SEC3">BUILDING 8-BIT, 16-BIT AND 32-BIT LIBRARIES</a>
19 <li><a name="TOC4" href="#SEC4">BUILDING SHARED AND STATIC LIBRARIES</a>
20 <li><a name="TOC5" href="#SEC5">C++ SUPPORT</a>
21 <li><a name="TOC6" href="#SEC6">UTF-8, UTF-16 AND UTF-32 SUPPORT</a>
22 <li><a name="TOC7" href="#SEC7">UNICODE CHARACTER PROPERTY SUPPORT</a>
23 <li><a name="TOC8" href="#SEC8">JUST-IN-TIME COMPILER SUPPORT</a>
24 <li><a name="TOC9" href="#SEC9">CODE VALUE OF NEWLINE</a>
25 <li><a name="TOC10" href="#SEC10">WHAT \R MATCHES</a>
26 <li><a name="TOC11" href="#SEC11">POSIX MALLOC USAGE</a>
27 <li><a name="TOC12" href="#SEC12">HANDLING VERY LARGE PATTERNS</a>
28 <li><a name="TOC13" href="#SEC13">AVOIDING EXCESSIVE STACK USAGE</a>
29 <li><a name="TOC14" href="#SEC14">LIMITING PCRE RESOURCE USAGE</a>
30 <li><a name="TOC15" href="#SEC15">CREATING CHARACTER TABLES AT BUILD TIME</a>
31 <li><a name="TOC16" href="#SEC16">USING EBCDIC CODE</a>
32 <li><a name="TOC17" href="#SEC17">PCREGREP OPTIONS FOR COMPRESSED FILE SUPPORT</a>
33 <li><a name="TOC18" href="#SEC18">PCREGREP BUFFER SIZE</a>
34 <li><a name="TOC19" href="#SEC19">PCRETEST OPTION FOR LIBREADLINE SUPPORT</a>
35 <li><a name="TOC20" href="#SEC20">DEBUGGING WITH VALGRIND SUPPORT</a>
36 <li><a name="TOC21" href="#SEC21">CODE COVERAGE REPORTING</a>
37 <li><a name="TOC22" href="#SEC22">SEE ALSO</a>
38 <li><a name="TOC23" href="#SEC23">AUTHOR</a>
39 <li><a name="TOC24" href="#SEC24">REVISION</a>
41 <br><a name="SEC1" href="#TOC1">BUILDING PCRE</a><br>
43 PCRE is distributed with a <b>configure</b> script that can be used to build the
44 library in Unix-like environments using the applications known as Autotools.
45 Also in the distribution are files to support building using <b>CMake</b>
46 instead of <b>configure</b>. The text file
47 <a href="README.txt"><b>README</b></a>
48 contains general information about building with Autotools (some of which is
49 repeated below), and also has some comments about building on various operating
50 systems. There is a lot more information about building PCRE without using
51 Autotools (including information about using <b>CMake</b> and building "by
52 hand") in the text file called
53 <a href="NON-AUTOTOOLS-BUILD.txt"><b>NON-AUTOTOOLS-BUILD</b>.</a>
54 You should consult this file as well as the
55 <a href="README.txt"><b>README</b></a>
56 file if you are building in a non-Unix-like environment.
58 <br><a name="SEC2" href="#TOC1">PCRE BUILD-TIME OPTIONS</a><br>
60 The rest of this document describes the optional features of PCRE that can be
61 selected when the library is compiled. It assumes use of the <b>configure</b>
62 script, where the optional features are selected or deselected by providing
63 options to <b>configure</b> before running the <b>make</b> command. However, the
64 same options can be selected in both Unix-like and non-Unix-like environments
65 using the GUI facility of <b>cmake-gui</b> if you are using <b>CMake</b> instead
66 of <b>configure</b> to build PCRE.
69 If you are not using Autotools or <b>CMake</b>, option selection can be done by
70 editing the <b>config.h</b> file, or by passing parameter settings to the
71 compiler, as described in
72 <a href="NON-AUTOTOOLS-BUILD.txt"><b>NON-AUTOTOOLS-BUILD</b>.</a>
75 The complete list of options for <b>configure</b> (which includes the standard
76 ones such as the selection of the installation directory) can be obtained by
79 ./configure --help
81 The following sections include descriptions of options whose names begin with
82 --enable or --disable. These settings specify changes to the defaults for the
83 <b>configure</b> command. Because of the way that <b>configure</b> works,
84 --enable and --disable always come in pairs, so the complementary option always
85 exists as well, but as it specifies the default, it is not described.
87 <br><a name="SEC3" href="#TOC1">BUILDING 8-BIT, 16-BIT AND 32-BIT LIBRARIES</a><br>
89 By default, a library called <b>libpcre</b> is built, containing functions that
90 take string arguments contained in vectors of bytes, either as single-byte
91 characters, or interpreted as UTF-8 strings. You can also build a separate
92 library, called <b>libpcre16</b>, in which strings are contained in vectors of
93 16-bit data units and interpreted either as single-unit characters or UTF-16
94 strings, by adding
98 to the <b>configure</b> command. You can also build yet another separate
99 library, called <b>libpcre32</b>, in which strings are contained in vectors of
100 32-bit data units and interpreted either as single-unit characters or UTF-32
101 strings, by adding
105 to the <b>configure</b> command. If you do not want the 8-bit library, add
109 as well. At least one of the three libraries must be built. Note that the C++
110 and POSIX wrappers are for the 8-bit library only, and that <b>pcregrep</b> is
111 an 8-bit program. None of these are built if you select only the 16-bit or
112 32-bit libraries.
114 <br><a name="SEC4" href="#TOC1">BUILDING SHARED AND STATIC LIBRARIES</a><br>
116 The Autotools PCRE building process uses <b>libtool</b> to build both shared and
117 static libraries by default. You can suppress one of these by adding one of
122 to the <b>configure</b> command, as required.
124 <br><a name="SEC5" href="#TOC1">C++ SUPPORT</a><br>
126 By default, if the 8-bit library is being built, the <b>configure</b> script
127 will search for a C++ compiler and C++ header files. If it finds them, it
128 automatically builds the C++ wrapper library (which supports only 8-bit
129 strings). You can disable this by adding
133 to the <b>configure</b> command.
135 <br><a name="SEC6" href="#TOC1">UTF-8, UTF-16 AND UTF-32 SUPPORT</a><br>
137 To build PCRE with support for UTF Unicode character strings, add
141 to the <b>configure</b> command. This setting applies to all three libraries,
142 adding support for UTF-8 to the 8-bit library, support for UTF-16 to the 16-bit
143 library, and support for UTF-32 to the to the 32-bit library. There are no
144 separate options for enabling UTF-8, UTF-16 and UTF-32 independently because
145 that would allow ridiculous settings such as requesting UTF-16 support while
146 building only the 8-bit library. It is not possible to build one library with
147 UTF support and another without in the same configuration. (For backwards
148 compatibility, --enable-utf8 is a synonym of --enable-utf.)
151 Of itself, this setting does not make PCRE treat strings as UTF-8, UTF-16 or
152 UTF-32. As well as compiling PCRE with this option, you also have have to set
153 the PCRE_UTF8, PCRE_UTF16 or PCRE_UTF32 option (as appropriate) when you call
154 one of the pattern compiling functions.
157 If you set --enable-utf when compiling in an EBCDIC environment, PCRE expects
158 its input to be either ASCII or UTF-8 (depending on the run-time option). It is
159 not possible to support both EBCDIC and UTF-8 codes in the same version of the
160 library. Consequently, --enable-utf and --enable-ebcdic are mutually
163 <br><a name="SEC7" href="#TOC1">UNICODE CHARACTER PROPERTY SUPPORT</a><br>
165 UTF support allows the libraries to process character codepoints up to 0x10ffff
166 in the strings that they handle. On its own, however, it does not provide any
167 facilities for accessing the properties of such characters. If you want to be
168 able to use the pattern escapes \P, \p, and \X, which refer to Unicode
169 character properties, you must add
173 to the <b>configure</b> command. This implies UTF support, even if you have
174 not explicitly requested it.
177 Including Unicode property support adds around 30K of tables to the PCRE
178 library. Only the general category properties such as <i>Lu</i> and <i>Nd</i> are
179 supported. Details are given in the
180 <a href="pcrepattern.html"><b>pcrepattern</b></a>
183 <br><a name="SEC8" href="#TOC1">JUST-IN-TIME COMPILER SUPPORT</a><br>
185 Just-in-time compiler support is included in the build by specifying
189 This support is available only for certain hardware architectures. If this
190 option is set for an unsupported architecture, a compile time error occurs.
191 See the
192 <a href="pcrejit.html"><b>pcrejit</b></a>
193 documentation for a discussion of JIT usage. When JIT support is enabled,
194 pcregrep automatically makes use of it, unless you add
198 to the "configure" command.
200 <br><a name="SEC9" href="#TOC1">CODE VALUE OF NEWLINE</a><br>
202 By default, PCRE interprets the linefeed (LF) character as indicating the end
203 of a line. This is the normal newline character on Unix-like systems. You can
204 compile PCRE to use carriage return (CR) instead, by adding
208 to the <b>configure</b> command. There is also a --enable-newline-is-lf option,
209 which explicitly specifies linefeed as the newline character.
212 Alternatively, you can specify that line endings are to be indicated by the two
213 character sequence CRLF. If you want this, add
217 to the <b>configure</b> command. There is a fourth option, specified by
221 which causes PCRE to recognize any of the three sequences CR, LF, or CRLF as
222 indicating a line ending. Finally, a fifth option, specified by
226 causes PCRE to recognize any Unicode newline sequence.
229 Whatever line ending convention is selected when PCRE is built can be
230 overridden when the library functions are called. At build time it is
231 conventional to use the standard for your operating system.
233 <br><a name="SEC10" href="#TOC1">WHAT \R MATCHES</a><br>
235 By default, the sequence \R in a pattern matches any Unicode newline sequence,
236 whatever has been selected as the line ending sequence. If you specify
240 the default is changed so that \R matches only CR, LF, or CRLF. Whatever is
241 selected when PCRE is built can be overridden when the library functions are
244 <br><a name="SEC11" href="#TOC1">POSIX MALLOC USAGE</a><br>
246 When the 8-bit library is called through the POSIX interface (see the
247 <a href="pcreposix.html"><b>pcreposix</b></a>
248 documentation), additional working storage is required for holding the pointers
249 to capturing substrings, because PCRE requires three integers per substring,
250 whereas the POSIX interface provides only two. If the number of expected
251 substrings is small, the wrapper function uses space on the stack, because this
252 is faster than using <b>malloc()</b> for each call. The default threshold above
253 which the stack is no longer used is 10; it can be changed by adding a setting
254 such as
258 to the <b>configure</b> command.
260 <br><a name="SEC12" href="#TOC1">HANDLING VERY LARGE PATTERNS</a><br>
262 Within a compiled pattern, offset values are used to point from one part to
263 another (for example, from an opening parenthesis to an alternation
264 metacharacter). By default, in the 8-bit and 16-bit libraries, two-byte values
265 are used for these offsets, leading to a maximum size for a compiled pattern of
266 around 64K. This is sufficient to handle all but the most gigantic patterns.
267 Nevertheless, some people do want to process truly enormous patterns, so it is
268 possible to compile PCRE to use three-byte or four-byte offsets by adding a
269 setting such as
273 to the <b>configure</b> command. The value given must be 2, 3, or 4. For the
274 16-bit library, a value of 3 is rounded up to 4. In these libraries, using
275 longer offsets slows down the operation of PCRE because it has to load
276 additional data when handling them. For the 32-bit library the value is always
277 4 and cannot be overridden; the value of --with-link-size is ignored.
279 <br><a name="SEC13" href="#TOC1">AVOIDING EXCESSIVE STACK USAGE</a><br>
281 When matching with the <b>pcre_exec()</b> function, PCRE implements backtracking
282 by making recursive calls to an internal function called <b>match()</b>. In
283 environments where the size of the stack is limited, this can severely limit
284 PCRE's operation. (The Unix environment does not usually suffer from this
285 problem, but it may sometimes be necessary to increase the maximum stack size.
286 There is a discussion in the
287 <a href="pcrestack.html"><b>pcrestack</b></a>
288 documentation.) An alternative approach to recursion that uses memory from the
289 heap to remember data, instead of using recursive function calls, has been
290 implemented to work round the problem of limited stack size. If you want to
291 build a version of PCRE that works this way, add
295 to the <b>configure</b> command. With this configuration, PCRE will use the
296 <b>pcre_stack_malloc</b> and <b>pcre_stack_free</b> variables to call memory
297 management functions. By default these point to <b>malloc()</b> and
298 <b>free()</b>, but you can replace the pointers so that your own functions are
299 used instead.
302 Separate functions are provided rather than using <b>pcre_malloc</b> and
303 <b>pcre_free</b> because the usage is very predictable: the block sizes
304 requested are always the same, and the blocks are always freed in reverse
305 order. A calling program might be able to implement optimized functions that
306 perform better than <b>malloc()</b> and <b>free()</b>. PCRE runs noticeably more
307 slowly when built in this way. This option affects only the <b>pcre_exec()</b>
308 function; it is not relevant for <b>pcre_dfa_exec()</b>.
310 <br><a name="SEC14" href="#TOC1">LIMITING PCRE RESOURCE USAGE</a><br>
312 Internally, PCRE has a function called <b>match()</b>, which it calls repeatedly
313 (sometimes recursively) when matching a pattern with the <b>pcre_exec()</b>
314 function. By controlling the maximum number of times this function may be
315 called during a single matching operation, a limit can be placed on the
316 resources used by a single call to <b>pcre_exec()</b>. The limit can be changed
317 at run time, as described in the
318 <a href="pcreapi.html"><b>pcreapi</b></a>
319 documentation. The default is 10 million, but this can be changed by adding a
320 setting such as
324 to the <b>configure</b> command. This setting has no effect on the
325 <b>pcre_dfa_exec()</b> matching function.
328 In some environments it is desirable to limit the depth of recursive calls of
329 <b>match()</b> more strictly than the total number of calls, in order to
330 restrict the maximum amount of stack (or heap, if --disable-stack-for-recursion
331 is specified) that is used. A second limit controls this; it defaults to the
332 value that is set for --with-match-limit, which imposes no additional
333 constraints. However, you can set a lower limit by adding, for example,
337 to the <b>configure</b> command. This value can also be overridden at run time.
339 <br><a name="SEC15" href="#TOC1">CREATING CHARACTER TABLES AT BUILD TIME</a><br>
341 PCRE uses fixed tables for processing characters whose code values are less
342 than 256. By default, PCRE is built with a set of tables that are distributed
343 in the file <i>pcre_chartables.c.dist</i>. These tables are for ASCII codes
344 only. If you add
348 to the <b>configure</b> command, the distributed tables are no longer used.
349 Instead, a program called <b>dftables</b> is compiled and run. This outputs the
350 source for new set of tables, created in the default locale of your C run-time
351 system. (This method of replacing the tables does not work if you are cross
352 compiling, because <b>dftables</b> is run on the local host. If you need to
353 create alternative tables when cross compiling, you will have to do so "by
356 <br><a name="SEC16" href="#TOC1">USING EBCDIC CODE</a><br>
358 PCRE assumes by default that it will run in an environment where the character
359 code is ASCII (or Unicode, which is a superset of ASCII). This is the case for
360 most computer operating systems. PCRE can, however, be compiled to run in an
361 EBCDIC environment by adding
365 to the <b>configure</b> command. This setting implies
366 --enable-rebuild-chartables. You should only use it if you know that you are in
367 an EBCDIC environment (for example, an IBM mainframe operating system). The
368 --enable-ebcdic option is incompatible with --enable-utf.
371 The EBCDIC character that corresponds to an ASCII LF is assumed to have the
372 value 0x15 by default. However, in some EBCDIC environments, 0x25 is used. In
373 such an environment you should use
377 as well as, or instead of, --enable-ebcdic. The EBCDIC character for CR has the
378 same value as in ASCII, namely, 0x0d. Whichever of 0x15 and 0x25 is <i>not</i>
379 chosen as LF is made to correspond to the Unicode NEL character (which, in
380 Unicode, is 0x85).
383 The options that select newline behaviour, such as --enable-newline-is-cr,
384 and equivalent run-time options, refer to these character values in an EBCDIC
387 <br><a name="SEC17" href="#TOC1">PCREGREP OPTIONS FOR COMPRESSED FILE SUPPORT</a><br>
389 By default, <b>pcregrep</b> reads all files as plain text. You can build it so
390 that it recognizes files whose names end in <b>.gz</b> or <b>.bz2</b>, and reads
391 them with <b>libz</b> or <b>libbz2</b>, respectively, by adding one or both of
396 to the <b>configure</b> command. These options naturally require that the
397 relevant libraries are installed on your system. Configuration will fail if
398 they are not.
400 <br><a name="SEC18" href="#TOC1">PCREGREP BUFFER SIZE</a><br>
402 <b>pcregrep</b> uses an internal buffer to hold a "window" on the file it is
403 scanning, in order to be able to output "before" and "after" lines when it
404 finds a match. The size of the buffer is controlled by a parameter whose
405 default value is 20K. The buffer itself is three times this size, but because
406 of the way it is used for holding "before" lines, the longest line that is
407 guaranteed to be processable is the parameter size. You can change the default
408 parameter value by adding, for example,
412 to the <b>configure</b> command. The caller of \fPpcregrep\fP can, however,
413 override this value by specifying a run-time option.
415 <br><a name="SEC19" href="#TOC1">PCRETEST OPTION FOR LIBREADLINE SUPPORT</a><br>
417 If you add
421 to the <b>configure</b> command, <b>pcretest</b> is linked with the
422 <b>libreadline</b> library, and when its input is from a terminal, it reads it
423 using the <b>readline()</b> function. This provides line-editing and history
424 facilities. Note that <b>libreadline</b> is GPL-licensed, so if you distribute a
425 binary of <b>pcretest</b> linked in this way, there may be licensing issues.
428 Setting this option causes the <b>-lreadline</b> option to be added to the
429 <b>pcretest</b> build. In many operating environments with a sytem-installed
430 <b>libreadline</b> this is sufficient. However, in some environments (e.g.
431 if an unmodified distribution version of readline is in use), some extra
432 configuration may be necessary. The INSTALL file for <b>libreadline</b> says
435 "Readline uses the termcap functions, but does not link with the
436 termcap or curses library itself, allowing applications which link
437 with readline the to choose an appropriate library."
439 If your environment has not been set up so that an appropriate library is
440 automatically included, you may need to add something like
444 immediately before the <b>configure</b> command.
446 <br><a name="SEC20" href="#TOC1">DEBUGGING WITH VALGRIND SUPPORT</a><br>
448 By adding the
452 option to to the <b>configure</b> command, PCRE will use valgrind annotations
453 to mark certain memory regions as unaddressable. This allows it to detect
454 invalid memory accesses, and is mostly useful for debugging PCRE itself.
456 <br><a name="SEC21" href="#TOC1">CODE COVERAGE REPORTING</a><br>
458 If your C compiler is gcc, you can build a version of PCRE that can generate a
459 code coverage report for its test suite. To enable this, you must install
460 <b>lcov</b> version 1.6 or above. Then specify
464 to the <b>configure</b> command and build PCRE in the usual way.
467 Note that using <b>ccache</b> (a caching C compiler) is incompatible with code
468 coverage reporting. If you have configured <b>ccache</b> to run automatically
469 on your system, you must set the environment variable
473 before running <b>make</b> to build PCRE, so that <b>ccache</b> is not used.
476 When --enable-coverage is used, the following addition targets are added to the
479 make coverage
481 This creates a fresh coverage report for the PCRE test suite. It is equivalent
482 to running "make coverage-reset", "make coverage-baseline", "make check", and
483 then "make coverage-report".
485 make coverage-reset
487 This zeroes the coverage counters, but does nothing else.
489 make coverage-baseline
491 This captures baseline coverage information.
493 make coverage-report
495 This creates the coverage report.
497 make coverage-clean-report
499 This removes the generated coverage report without cleaning the coverage data
502 make coverage-clean-data
504 This removes the captured coverage data without removing the coverage files
505 created at compile time (*.gcno).
507 make coverage-clean
509 This cleans all coverage data including the generated coverage report. For more
510 information about code coverage, see the <b>gcov</b> and <b>lcov</b>
513 <br><a name="SEC22" href="#TOC1">SEE ALSO</a><br>
515 <b>pcreapi</b>(3), <b>pcre16</b>, <b>pcre32</b>, <b>pcre_config</b>(3).
517 <br><a name="SEC23" href="#TOC1">AUTHOR</a><br>
519 Philip Hazel
521 University Computing Service
523 Cambridge CB2 3QH, England.
526 <br><a name="SEC24" href="#TOC1">REVISION</a><br>
528 Last updated: 12 May 2013
530 Copyright © 1997-2013 University of Cambridge.
533 Return to the <a href="index.html">PCRE index page</a>.