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1.1 misho 1: <html>
2: <head>
3: <title>pcrebuild specification</title>
4: </head>
5: <body bgcolor="#FFFFFF" text="#00005A" link="#0066FF" alink="#3399FF" vlink="#2222BB">
6: <h1>pcrebuild man page</h1>
7: <p>
8: Return to the <a href="index.html">PCRE index page</a>.
9: </p>
10: <p>
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.
14: <br>
15: <ul>
16: <li><a name="TOC1" href="#SEC1">PCRE BUILD-TIME OPTIONS</a>
1.1.1.2 misho 17: <li><a name="TOC2" href="#SEC2">BUILDING 8-BIT and 16-BIT LIBRARIES</a>
18: <li><a name="TOC3" href="#SEC3">BUILDING SHARED AND STATIC LIBRARIES</a>
19: <li><a name="TOC4" href="#SEC4">C++ SUPPORT</a>
20: <li><a name="TOC5" href="#SEC5">UTF-8 and UTF-16 SUPPORT</a>
21: <li><a name="TOC6" href="#SEC6">UNICODE CHARACTER PROPERTY SUPPORT</a>
22: <li><a name="TOC7" href="#SEC7">JUST-IN-TIME COMPILER SUPPORT</a>
23: <li><a name="TOC8" href="#SEC8">CODE VALUE OF NEWLINE</a>
24: <li><a name="TOC9" href="#SEC9">WHAT \R MATCHES</a>
25: <li><a name="TOC10" href="#SEC10">POSIX MALLOC USAGE</a>
26: <li><a name="TOC11" href="#SEC11">HANDLING VERY LARGE PATTERNS</a>
27: <li><a name="TOC12" href="#SEC12">AVOIDING EXCESSIVE STACK USAGE</a>
28: <li><a name="TOC13" href="#SEC13">LIMITING PCRE RESOURCE USAGE</a>
29: <li><a name="TOC14" href="#SEC14">CREATING CHARACTER TABLES AT BUILD TIME</a>
30: <li><a name="TOC15" href="#SEC15">USING EBCDIC CODE</a>
31: <li><a name="TOC16" href="#SEC16">PCREGREP OPTIONS FOR COMPRESSED FILE SUPPORT</a>
32: <li><a name="TOC17" href="#SEC17">PCREGREP BUFFER SIZE</a>
33: <li><a name="TOC18" href="#SEC18">PCRETEST OPTION FOR LIBREADLINE SUPPORT</a>
34: <li><a name="TOC19" href="#SEC19">SEE ALSO</a>
35: <li><a name="TOC20" href="#SEC20">AUTHOR</a>
36: <li><a name="TOC21" href="#SEC21">REVISION</a>
1.1 misho 37: </ul>
38: <br><a name="SEC1" href="#TOC1">PCRE BUILD-TIME OPTIONS</a><br>
39: <P>
40: This document describes the optional features of PCRE that can be selected when
41: the library is compiled. It assumes use of the <b>configure</b> script, where
42: the optional features are selected or deselected by providing options to
43: <b>configure</b> before running the <b>make</b> command. However, the same
44: options can be selected in both Unix-like and non-Unix-like environments using
45: the GUI facility of <b>cmake-gui</b> if you are using <b>CMake</b> instead of
46: <b>configure</b> to build PCRE.
47: </P>
48: <P>
49: There is a lot more information about building PCRE in non-Unix-like
50: environments in the file called <i>NON_UNIX_USE</i>, which is part of the PCRE
51: distribution. You should consult this file as well as the <i>README</i> file if
52: you are building in a non-Unix-like environment.
53: </P>
54: <P>
55: The complete list of options for <b>configure</b> (which includes the standard
56: ones such as the selection of the installation directory) can be obtained by
57: running
58: <pre>
59: ./configure --help
60: </pre>
61: The following sections include descriptions of options whose names begin with
62: --enable or --disable. These settings specify changes to the defaults for the
63: <b>configure</b> command. Because of the way that <b>configure</b> works,
64: --enable and --disable always come in pairs, so the complementary option always
65: exists as well, but as it specifies the default, it is not described.
66: </P>
1.1.1.2 misho 67: <br><a name="SEC2" href="#TOC1">BUILDING 8-BIT and 16-BIT LIBRARIES</a><br>
68: <P>
69: By default, a library called <b>libpcre</b> is built, containing functions that
70: take string arguments contained in vectors of bytes, either as single-byte
71: characters, or interpreted as UTF-8 strings. You can also build a separate
72: library, called <b>libpcre16</b>, in which strings are contained in vectors of
73: 16-bit data units and interpreted either as single-unit characters or UTF-16
74: strings, by adding
75: <pre>
76: --enable-pcre16
77: </pre>
78: to the <b>configure</b> command. If you do not want the 8-bit library, add
79: <pre>
80: --disable-pcre8
81: </pre>
82: as well. At least one of the two libraries must be built. Note that the C++ and
83: POSIX wrappers are for the 8-bit library only, and that <b>pcregrep</b> is an
84: 8-bit program. None of these are built if you select only the 16-bit library.
85: </P>
86: <br><a name="SEC3" href="#TOC1">BUILDING SHARED AND STATIC LIBRARIES</a><br>
1.1 misho 87: <P>
88: The PCRE building process uses <b>libtool</b> to build both shared and static
89: Unix libraries by default. You can suppress one of these by adding one of
90: <pre>
91: --disable-shared
92: --disable-static
93: </pre>
94: to the <b>configure</b> command, as required.
95: </P>
1.1.1.2 misho 96: <br><a name="SEC4" href="#TOC1">C++ SUPPORT</a><br>
1.1 misho 97: <P>
1.1.1.2 misho 98: By default, if the 8-bit library is being built, the <b>configure</b> script
99: will search for a C++ compiler and C++ header files. If it finds them, it
100: automatically builds the C++ wrapper library (which supports only 8-bit
101: strings). You can disable this by adding
1.1 misho 102: <pre>
103: --disable-cpp
104: </pre>
105: to the <b>configure</b> command.
106: </P>
1.1.1.2 misho 107: <br><a name="SEC5" href="#TOC1">UTF-8 and UTF-16 SUPPORT</a><br>
1.1 misho 108: <P>
1.1.1.2 misho 109: To build PCRE with support for UTF Unicode character strings, add
1.1 misho 110: <pre>
1.1.1.2 misho 111: --enable-utf
1.1 misho 112: </pre>
1.1.1.2 misho 113: to the <b>configure</b> command. This setting applies to both libraries, adding
114: support for UTF-8 to the 8-bit library and support for UTF-16 to the 16-bit
115: library. There are no separate options for enabling UTF-8 and UTF-16
116: independently because that would allow ridiculous settings such as requesting
117: UTF-16 support while building only the 8-bit library. It is not possible to
118: build one library with UTF support and the other without in the same
119: configuration. (For backwards compatibility, --enable-utf8 is a synonym of
120: --enable-utf.)
121: </P>
122: <P>
123: Of itself, this setting does not make PCRE treat strings as UTF-8 or UTF-16. As
124: well as compiling PCRE with this option, you also have have to set the
125: PCRE_UTF8 or PCRE_UTF16 option when you call one of the pattern compiling
126: functions.
1.1 misho 127: </P>
128: <P>
1.1.1.2 misho 129: If you set --enable-utf when compiling in an EBCDIC environment, PCRE expects
1.1.1.3 ! misho 130: its input to be either ASCII or UTF-8 (depending on the run-time option). It is
1.1 misho 131: not possible to support both EBCDIC and UTF-8 codes in the same version of the
1.1.1.2 misho 132: library. Consequently, --enable-utf and --enable-ebcdic are mutually
1.1 misho 133: exclusive.
134: </P>
1.1.1.2 misho 135: <br><a name="SEC6" href="#TOC1">UNICODE CHARACTER PROPERTY SUPPORT</a><br>
1.1 misho 136: <P>
1.1.1.2 misho 137: UTF support allows the libraries to process character codepoints up to 0x10ffff
138: in the strings that they handle. On its own, however, it does not provide any
1.1 misho 139: facilities for accessing the properties of such characters. If you want to be
140: able to use the pattern escapes \P, \p, and \X, which refer to Unicode
141: character properties, you must add
142: <pre>
143: --enable-unicode-properties
144: </pre>
1.1.1.2 misho 145: to the <b>configure</b> command. This implies UTF support, even if you have
1.1 misho 146: not explicitly requested it.
147: </P>
148: <P>
149: Including Unicode property support adds around 30K of tables to the PCRE
150: library. Only the general category properties such as <i>Lu</i> and <i>Nd</i> are
151: supported. Details are given in the
152: <a href="pcrepattern.html"><b>pcrepattern</b></a>
153: documentation.
154: </P>
1.1.1.2 misho 155: <br><a name="SEC7" href="#TOC1">JUST-IN-TIME COMPILER SUPPORT</a><br>
1.1 misho 156: <P>
157: Just-in-time compiler support is included in the build by specifying
158: <pre>
159: --enable-jit
160: </pre>
161: This support is available only for certain hardware architectures. If this
162: option is set for an unsupported architecture, a compile time error occurs.
163: See the
164: <a href="pcrejit.html"><b>pcrejit</b></a>
165: documentation for a discussion of JIT usage. When JIT support is enabled,
166: pcregrep automatically makes use of it, unless you add
167: <pre>
168: --disable-pcregrep-jit
169: </pre>
170: to the "configure" command.
171: </P>
1.1.1.2 misho 172: <br><a name="SEC8" href="#TOC1">CODE VALUE OF NEWLINE</a><br>
1.1 misho 173: <P>
174: By default, PCRE interprets the linefeed (LF) character as indicating the end
175: of a line. This is the normal newline character on Unix-like systems. You can
176: compile PCRE to use carriage return (CR) instead, by adding
177: <pre>
178: --enable-newline-is-cr
179: </pre>
180: to the <b>configure</b> command. There is also a --enable-newline-is-lf option,
181: which explicitly specifies linefeed as the newline character.
182: <br>
183: <br>
184: Alternatively, you can specify that line endings are to be indicated by the two
185: character sequence CRLF. If you want this, add
186: <pre>
187: --enable-newline-is-crlf
188: </pre>
189: to the <b>configure</b> command. There is a fourth option, specified by
190: <pre>
191: --enable-newline-is-anycrlf
192: </pre>
193: which causes PCRE to recognize any of the three sequences CR, LF, or CRLF as
194: indicating a line ending. Finally, a fifth option, specified by
195: <pre>
196: --enable-newline-is-any
197: </pre>
198: causes PCRE to recognize any Unicode newline sequence.
199: </P>
200: <P>
201: Whatever line ending convention is selected when PCRE is built can be
202: overridden when the library functions are called. At build time it is
203: conventional to use the standard for your operating system.
204: </P>
1.1.1.2 misho 205: <br><a name="SEC9" href="#TOC1">WHAT \R MATCHES</a><br>
1.1 misho 206: <P>
207: By default, the sequence \R in a pattern matches any Unicode newline sequence,
208: whatever has been selected as the line ending sequence. If you specify
209: <pre>
210: --enable-bsr-anycrlf
211: </pre>
212: the default is changed so that \R matches only CR, LF, or CRLF. Whatever is
213: selected when PCRE is built can be overridden when the library functions are
214: called.
215: </P>
1.1.1.2 misho 216: <br><a name="SEC10" href="#TOC1">POSIX MALLOC USAGE</a><br>
1.1 misho 217: <P>
1.1.1.2 misho 218: When the 8-bit library is called through the POSIX interface (see the
1.1 misho 219: <a href="pcreposix.html"><b>pcreposix</b></a>
220: documentation), additional working storage is required for holding the pointers
221: to capturing substrings, because PCRE requires three integers per substring,
222: whereas the POSIX interface provides only two. If the number of expected
223: substrings is small, the wrapper function uses space on the stack, because this
224: is faster than using <b>malloc()</b> for each call. The default threshold above
225: which the stack is no longer used is 10; it can be changed by adding a setting
226: such as
227: <pre>
228: --with-posix-malloc-threshold=20
229: </pre>
230: to the <b>configure</b> command.
231: </P>
1.1.1.2 misho 232: <br><a name="SEC11" href="#TOC1">HANDLING VERY LARGE PATTERNS</a><br>
1.1 misho 233: <P>
234: Within a compiled pattern, offset values are used to point from one part to
235: another (for example, from an opening parenthesis to an alternation
236: metacharacter). By default, two-byte values are used for these offsets, leading
237: to a maximum size for a compiled pattern of around 64K. This is sufficient to
238: handle all but the most gigantic patterns. Nevertheless, some people do want to
1.1.1.2 misho 239: process truly enormous patterns, so it is possible to compile PCRE to use
1.1 misho 240: three-byte or four-byte offsets by adding a setting such as
241: <pre>
242: --with-link-size=3
243: </pre>
1.1.1.2 misho 244: to the <b>configure</b> command. The value given must be 2, 3, or 4. For the
245: 16-bit library, a value of 3 is rounded up to 4. Using longer offsets slows
246: down the operation of PCRE because it has to load additional data when handling
247: them.
1.1 misho 248: </P>
1.1.1.2 misho 249: <br><a name="SEC12" href="#TOC1">AVOIDING EXCESSIVE STACK USAGE</a><br>
1.1 misho 250: <P>
251: When matching with the <b>pcre_exec()</b> function, PCRE implements backtracking
252: by making recursive calls to an internal function called <b>match()</b>. In
253: environments where the size of the stack is limited, this can severely limit
254: PCRE's operation. (The Unix environment does not usually suffer from this
255: problem, but it may sometimes be necessary to increase the maximum stack size.
256: There is a discussion in the
257: <a href="pcrestack.html"><b>pcrestack</b></a>
258: documentation.) An alternative approach to recursion that uses memory from the
259: heap to remember data, instead of using recursive function calls, has been
260: implemented to work round the problem of limited stack size. If you want to
261: build a version of PCRE that works this way, add
262: <pre>
263: --disable-stack-for-recursion
264: </pre>
265: to the <b>configure</b> command. With this configuration, PCRE will use the
266: <b>pcre_stack_malloc</b> and <b>pcre_stack_free</b> variables to call memory
267: management functions. By default these point to <b>malloc()</b> and
268: <b>free()</b>, but you can replace the pointers so that your own functions are
269: used instead.
270: </P>
271: <P>
272: Separate functions are provided rather than using <b>pcre_malloc</b> and
273: <b>pcre_free</b> because the usage is very predictable: the block sizes
274: requested are always the same, and the blocks are always freed in reverse
275: order. A calling program might be able to implement optimized functions that
276: perform better than <b>malloc()</b> and <b>free()</b>. PCRE runs noticeably more
277: slowly when built in this way. This option affects only the <b>pcre_exec()</b>
278: function; it is not relevant for <b>pcre_dfa_exec()</b>.
279: </P>
1.1.1.2 misho 280: <br><a name="SEC13" href="#TOC1">LIMITING PCRE RESOURCE USAGE</a><br>
1.1 misho 281: <P>
282: Internally, PCRE has a function called <b>match()</b>, which it calls repeatedly
283: (sometimes recursively) when matching a pattern with the <b>pcre_exec()</b>
284: function. By controlling the maximum number of times this function may be
285: called during a single matching operation, a limit can be placed on the
286: resources used by a single call to <b>pcre_exec()</b>. The limit can be changed
287: at run time, as described in the
288: <a href="pcreapi.html"><b>pcreapi</b></a>
289: documentation. The default is 10 million, but this can be changed by adding a
290: setting such as
291: <pre>
292: --with-match-limit=500000
293: </pre>
294: to the <b>configure</b> command. This setting has no effect on the
295: <b>pcre_dfa_exec()</b> matching function.
296: </P>
297: <P>
298: In some environments it is desirable to limit the depth of recursive calls of
299: <b>match()</b> more strictly than the total number of calls, in order to
300: restrict the maximum amount of stack (or heap, if --disable-stack-for-recursion
301: is specified) that is used. A second limit controls this; it defaults to the
302: value that is set for --with-match-limit, which imposes no additional
303: constraints. However, you can set a lower limit by adding, for example,
304: <pre>
305: --with-match-limit-recursion=10000
306: </pre>
307: to the <b>configure</b> command. This value can also be overridden at run time.
308: </P>
1.1.1.2 misho 309: <br><a name="SEC14" href="#TOC1">CREATING CHARACTER TABLES AT BUILD TIME</a><br>
1.1 misho 310: <P>
311: PCRE uses fixed tables for processing characters whose code values are less
312: than 256. By default, PCRE is built with a set of tables that are distributed
313: in the file <i>pcre_chartables.c.dist</i>. These tables are for ASCII codes
314: only. If you add
315: <pre>
316: --enable-rebuild-chartables
317: </pre>
318: to the <b>configure</b> command, the distributed tables are no longer used.
319: Instead, a program called <b>dftables</b> is compiled and run. This outputs the
1.1.1.3 ! misho 320: source for new set of tables, created in the default locale of your C run-time
1.1 misho 321: system. (This method of replacing the tables does not work if you are cross
322: compiling, because <b>dftables</b> is run on the local host. If you need to
323: create alternative tables when cross compiling, you will have to do so "by
324: hand".)
325: </P>
1.1.1.2 misho 326: <br><a name="SEC15" href="#TOC1">USING EBCDIC CODE</a><br>
1.1 misho 327: <P>
328: PCRE assumes by default that it will run in an environment where the character
329: code is ASCII (or Unicode, which is a superset of ASCII). This is the case for
330: most computer operating systems. PCRE can, however, be compiled to run in an
331: EBCDIC environment by adding
332: <pre>
333: --enable-ebcdic
334: </pre>
335: to the <b>configure</b> command. This setting implies
336: --enable-rebuild-chartables. You should only use it if you know that you are in
337: an EBCDIC environment (for example, an IBM mainframe operating system). The
1.1.1.2 misho 338: --enable-ebcdic option is incompatible with --enable-utf.
1.1 misho 339: </P>
1.1.1.2 misho 340: <br><a name="SEC16" href="#TOC1">PCREGREP OPTIONS FOR COMPRESSED FILE SUPPORT</a><br>
1.1 misho 341: <P>
342: By default, <b>pcregrep</b> reads all files as plain text. You can build it so
343: that it recognizes files whose names end in <b>.gz</b> or <b>.bz2</b>, and reads
344: them with <b>libz</b> or <b>libbz2</b>, respectively, by adding one or both of
345: <pre>
346: --enable-pcregrep-libz
347: --enable-pcregrep-libbz2
348: </pre>
349: to the <b>configure</b> command. These options naturally require that the
350: relevant libraries are installed on your system. Configuration will fail if
351: they are not.
352: </P>
1.1.1.2 misho 353: <br><a name="SEC17" href="#TOC1">PCREGREP BUFFER SIZE</a><br>
1.1 misho 354: <P>
355: <b>pcregrep</b> uses an internal buffer to hold a "window" on the file it is
356: scanning, in order to be able to output "before" and "after" lines when it
357: finds a match. The size of the buffer is controlled by a parameter whose
358: default value is 20K. The buffer itself is three times this size, but because
359: of the way it is used for holding "before" lines, the longest line that is
360: guaranteed to be processable is the parameter size. You can change the default
361: parameter value by adding, for example,
362: <pre>
363: --with-pcregrep-bufsize=50K
364: </pre>
365: to the <b>configure</b> command. The caller of \fPpcregrep\fP can, however,
366: override this value by specifying a run-time option.
367: </P>
1.1.1.2 misho 368: <br><a name="SEC18" href="#TOC1">PCRETEST OPTION FOR LIBREADLINE SUPPORT</a><br>
1.1 misho 369: <P>
370: If you add
371: <pre>
372: --enable-pcretest-libreadline
373: </pre>
374: to the <b>configure</b> command, <b>pcretest</b> is linked with the
375: <b>libreadline</b> library, and when its input is from a terminal, it reads it
376: using the <b>readline()</b> function. This provides line-editing and history
377: facilities. Note that <b>libreadline</b> is GPL-licensed, so if you distribute a
378: binary of <b>pcretest</b> linked in this way, there may be licensing issues.
379: </P>
380: <P>
381: Setting this option causes the <b>-lreadline</b> option to be added to the
382: <b>pcretest</b> build. In many operating environments with a sytem-installed
383: <b>libreadline</b> this is sufficient. However, in some environments (e.g.
384: if an unmodified distribution version of readline is in use), some extra
385: configuration may be necessary. The INSTALL file for <b>libreadline</b> says
386: this:
387: <pre>
388: "Readline uses the termcap functions, but does not link with the
389: termcap or curses library itself, allowing applications which link
390: with readline the to choose an appropriate library."
391: </pre>
392: If your environment has not been set up so that an appropriate library is
393: automatically included, you may need to add something like
394: <pre>
395: LIBS="-ncurses"
396: </pre>
397: immediately before the <b>configure</b> command.
398: </P>
1.1.1.2 misho 399: <br><a name="SEC19" href="#TOC1">SEE ALSO</a><br>
1.1 misho 400: <P>
1.1.1.2 misho 401: <b>pcreapi</b>(3), <b>pcre16</b>, <b>pcre_config</b>(3).
1.1 misho 402: </P>
1.1.1.2 misho 403: <br><a name="SEC20" href="#TOC1">AUTHOR</a><br>
1.1 misho 404: <P>
405: Philip Hazel
406: <br>
407: University Computing Service
408: <br>
409: Cambridge CB2 3QH, England.
410: <br>
411: </P>
1.1.1.2 misho 412: <br><a name="SEC21" href="#TOC1">REVISION</a><br>
1.1 misho 413: <P>
1.1.1.2 misho 414: Last updated: 07 January 2012
1.1 misho 415: <br>
1.1.1.2 misho 416: Copyright © 1997-2012 University of Cambridge.
1.1 misho 417: <br>
418: <p>
419: Return to the <a href="index.html">PCRE index page</a>.
420: </p>
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