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! 2: <head>
! 3: <title>pcrebuild specification</title>
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! 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>
! 17: <li><a name="TOC2" href="#SEC2">BUILDING SHARED AND STATIC LIBRARIES</a>
! 18: <li><a name="TOC3" href="#SEC3">C++ SUPPORT</a>
! 19: <li><a name="TOC4" href="#SEC4">UTF-8 SUPPORT</a>
! 20: <li><a name="TOC5" href="#SEC5">UNICODE CHARACTER PROPERTY SUPPORT</a>
! 21: <li><a name="TOC6" href="#SEC6">JUST-IN-TIME COMPILER SUPPORT</a>
! 22: <li><a name="TOC7" href="#SEC7">CODE VALUE OF NEWLINE</a>
! 23: <li><a name="TOC8" href="#SEC8">WHAT \R MATCHES</a>
! 24: <li><a name="TOC9" href="#SEC9">POSIX MALLOC USAGE</a>
! 25: <li><a name="TOC10" href="#SEC10">HANDLING VERY LARGE PATTERNS</a>
! 26: <li><a name="TOC11" href="#SEC11">AVOIDING EXCESSIVE STACK USAGE</a>
! 27: <li><a name="TOC12" href="#SEC12">LIMITING PCRE RESOURCE USAGE</a>
! 28: <li><a name="TOC13" href="#SEC13">CREATING CHARACTER TABLES AT BUILD TIME</a>
! 29: <li><a name="TOC14" href="#SEC14">USING EBCDIC CODE</a>
! 30: <li><a name="TOC15" href="#SEC15">PCREGREP OPTIONS FOR COMPRESSED FILE SUPPORT</a>
! 31: <li><a name="TOC16" href="#SEC16">PCREGREP BUFFER SIZE</a>
! 32: <li><a name="TOC17" href="#SEC17">PCRETEST OPTION FOR LIBREADLINE SUPPORT</a>
! 33: <li><a name="TOC18" href="#SEC18">SEE ALSO</a>
! 34: <li><a name="TOC19" href="#SEC19">AUTHOR</a>
! 35: <li><a name="TOC20" href="#SEC20">REVISION</a>
! 36: </ul>
! 37: <br><a name="SEC1" href="#TOC1">PCRE BUILD-TIME OPTIONS</a><br>
! 38: <P>
! 39: This document describes the optional features of PCRE that can be selected when
! 40: the library is compiled. It assumes use of the <b>configure</b> script, where
! 41: the optional features are selected or deselected by providing options to
! 42: <b>configure</b> before running the <b>make</b> command. However, the same
! 43: options can be selected in both Unix-like and non-Unix-like environments using
! 44: the GUI facility of <b>cmake-gui</b> if you are using <b>CMake</b> instead of
! 45: <b>configure</b> to build PCRE.
! 46: </P>
! 47: <P>
! 48: There is a lot more information about building PCRE in non-Unix-like
! 49: environments in the file called <i>NON_UNIX_USE</i>, which is part of the PCRE
! 50: distribution. You should consult this file as well as the <i>README</i> file if
! 51: you are building in a non-Unix-like environment.
! 52: </P>
! 53: <P>
! 54: The complete list of options for <b>configure</b> (which includes the standard
! 55: ones such as the selection of the installation directory) can be obtained by
! 56: running
! 57: <pre>
! 58: ./configure --help
! 59: </pre>
! 60: The following sections include descriptions of options whose names begin with
! 61: --enable or --disable. These settings specify changes to the defaults for the
! 62: <b>configure</b> command. Because of the way that <b>configure</b> works,
! 63: --enable and --disable always come in pairs, so the complementary option always
! 64: exists as well, but as it specifies the default, it is not described.
! 65: </P>
! 66: <br><a name="SEC2" href="#TOC1">BUILDING SHARED AND STATIC LIBRARIES</a><br>
! 67: <P>
! 68: The PCRE building process uses <b>libtool</b> to build both shared and static
! 69: Unix libraries by default. You can suppress one of these by adding one of
! 70: <pre>
! 71: --disable-shared
! 72: --disable-static
! 73: </pre>
! 74: to the <b>configure</b> command, as required.
! 75: </P>
! 76: <br><a name="SEC3" href="#TOC1">C++ SUPPORT</a><br>
! 77: <P>
! 78: By default, the <b>configure</b> script will search for a C++ compiler and C++
! 79: header files. If it finds them, it automatically builds the C++ wrapper library
! 80: for PCRE. You can disable this by adding
! 81: <pre>
! 82: --disable-cpp
! 83: </pre>
! 84: to the <b>configure</b> command.
! 85: </P>
! 86: <br><a name="SEC4" href="#TOC1">UTF-8 SUPPORT</a><br>
! 87: <P>
! 88: To build PCRE with support for UTF-8 Unicode character strings, add
! 89: <pre>
! 90: --enable-utf8
! 91: </pre>
! 92: to the <b>configure</b> command. Of itself, this does not make PCRE treat
! 93: strings as UTF-8. As well as compiling PCRE with this option, you also have
! 94: have to set the PCRE_UTF8 option when you call the <b>pcre_compile()</b>
! 95: or <b>pcre_compile2()</b> functions.
! 96: </P>
! 97: <P>
! 98: If you set --enable-utf8 when compiling in an EBCDIC environment, PCRE expects
! 99: its input to be either ASCII or UTF-8 (depending on the runtime option). It is
! 100: not possible to support both EBCDIC and UTF-8 codes in the same version of the
! 101: library. Consequently, --enable-utf8 and --enable-ebcdic are mutually
! 102: exclusive.
! 103: </P>
! 104: <br><a name="SEC5" href="#TOC1">UNICODE CHARACTER PROPERTY SUPPORT</a><br>
! 105: <P>
! 106: UTF-8 support allows PCRE to process character values greater than 255 in the
! 107: strings that it handles. On its own, however, it does not provide any
! 108: facilities for accessing the properties of such characters. If you want to be
! 109: able to use the pattern escapes \P, \p, and \X, which refer to Unicode
! 110: character properties, you must add
! 111: <pre>
! 112: --enable-unicode-properties
! 113: </pre>
! 114: to the <b>configure</b> command. This implies UTF-8 support, even if you have
! 115: not explicitly requested it.
! 116: </P>
! 117: <P>
! 118: Including Unicode property support adds around 30K of tables to the PCRE
! 119: library. Only the general category properties such as <i>Lu</i> and <i>Nd</i> are
! 120: supported. Details are given in the
! 121: <a href="pcrepattern.html"><b>pcrepattern</b></a>
! 122: documentation.
! 123: </P>
! 124: <br><a name="SEC6" href="#TOC1">JUST-IN-TIME COMPILER SUPPORT</a><br>
! 125: <P>
! 126: Just-in-time compiler support is included in the build by specifying
! 127: <pre>
! 128: --enable-jit
! 129: </pre>
! 130: This support is available only for certain hardware architectures. If this
! 131: option is set for an unsupported architecture, a compile time error occurs.
! 132: See the
! 133: <a href="pcrejit.html"><b>pcrejit</b></a>
! 134: documentation for a discussion of JIT usage. When JIT support is enabled,
! 135: pcregrep automatically makes use of it, unless you add
! 136: <pre>
! 137: --disable-pcregrep-jit
! 138: </pre>
! 139: to the "configure" command.
! 140: </P>
! 141: <br><a name="SEC7" href="#TOC1">CODE VALUE OF NEWLINE</a><br>
! 142: <P>
! 143: By default, PCRE interprets the linefeed (LF) character as indicating the end
! 144: of a line. This is the normal newline character on Unix-like systems. You can
! 145: compile PCRE to use carriage return (CR) instead, by adding
! 146: <pre>
! 147: --enable-newline-is-cr
! 148: </pre>
! 149: to the <b>configure</b> command. There is also a --enable-newline-is-lf option,
! 150: which explicitly specifies linefeed as the newline character.
! 151: <br>
! 152: <br>
! 153: Alternatively, you can specify that line endings are to be indicated by the two
! 154: character sequence CRLF. If you want this, add
! 155: <pre>
! 156: --enable-newline-is-crlf
! 157: </pre>
! 158: to the <b>configure</b> command. There is a fourth option, specified by
! 159: <pre>
! 160: --enable-newline-is-anycrlf
! 161: </pre>
! 162: which causes PCRE to recognize any of the three sequences CR, LF, or CRLF as
! 163: indicating a line ending. Finally, a fifth option, specified by
! 164: <pre>
! 165: --enable-newline-is-any
! 166: </pre>
! 167: causes PCRE to recognize any Unicode newline sequence.
! 168: </P>
! 169: <P>
! 170: Whatever line ending convention is selected when PCRE is built can be
! 171: overridden when the library functions are called. At build time it is
! 172: conventional to use the standard for your operating system.
! 173: </P>
! 174: <br><a name="SEC8" href="#TOC1">WHAT \R MATCHES</a><br>
! 175: <P>
! 176: By default, the sequence \R in a pattern matches any Unicode newline sequence,
! 177: whatever has been selected as the line ending sequence. If you specify
! 178: <pre>
! 179: --enable-bsr-anycrlf
! 180: </pre>
! 181: the default is changed so that \R matches only CR, LF, or CRLF. Whatever is
! 182: selected when PCRE is built can be overridden when the library functions are
! 183: called.
! 184: </P>
! 185: <br><a name="SEC9" href="#TOC1">POSIX MALLOC USAGE</a><br>
! 186: <P>
! 187: When PCRE is called through the POSIX interface (see the
! 188: <a href="pcreposix.html"><b>pcreposix</b></a>
! 189: documentation), additional working storage is required for holding the pointers
! 190: to capturing substrings, because PCRE requires three integers per substring,
! 191: whereas the POSIX interface provides only two. If the number of expected
! 192: substrings is small, the wrapper function uses space on the stack, because this
! 193: is faster than using <b>malloc()</b> for each call. The default threshold above
! 194: which the stack is no longer used is 10; it can be changed by adding a setting
! 195: such as
! 196: <pre>
! 197: --with-posix-malloc-threshold=20
! 198: </pre>
! 199: to the <b>configure</b> command.
! 200: </P>
! 201: <br><a name="SEC10" href="#TOC1">HANDLING VERY LARGE PATTERNS</a><br>
! 202: <P>
! 203: Within a compiled pattern, offset values are used to point from one part to
! 204: another (for example, from an opening parenthesis to an alternation
! 205: metacharacter). By default, two-byte values are used for these offsets, leading
! 206: to a maximum size for a compiled pattern of around 64K. This is sufficient to
! 207: handle all but the most gigantic patterns. Nevertheless, some people do want to
! 208: process truyl enormous patterns, so it is possible to compile PCRE to use
! 209: three-byte or four-byte offsets by adding a setting such as
! 210: <pre>
! 211: --with-link-size=3
! 212: </pre>
! 213: to the <b>configure</b> command. The value given must be 2, 3, or 4. Using
! 214: longer offsets slows down the operation of PCRE because it has to load
! 215: additional bytes when handling them.
! 216: </P>
! 217: <br><a name="SEC11" href="#TOC1">AVOIDING EXCESSIVE STACK USAGE</a><br>
! 218: <P>
! 219: When matching with the <b>pcre_exec()</b> function, PCRE implements backtracking
! 220: by making recursive calls to an internal function called <b>match()</b>. In
! 221: environments where the size of the stack is limited, this can severely limit
! 222: PCRE's operation. (The Unix environment does not usually suffer from this
! 223: problem, but it may sometimes be necessary to increase the maximum stack size.
! 224: There is a discussion in the
! 225: <a href="pcrestack.html"><b>pcrestack</b></a>
! 226: documentation.) An alternative approach to recursion that uses memory from the
! 227: heap to remember data, instead of using recursive function calls, has been
! 228: implemented to work round the problem of limited stack size. If you want to
! 229: build a version of PCRE that works this way, add
! 230: <pre>
! 231: --disable-stack-for-recursion
! 232: </pre>
! 233: to the <b>configure</b> command. With this configuration, PCRE will use the
! 234: <b>pcre_stack_malloc</b> and <b>pcre_stack_free</b> variables to call memory
! 235: management functions. By default these point to <b>malloc()</b> and
! 236: <b>free()</b>, but you can replace the pointers so that your own functions are
! 237: used instead.
! 238: </P>
! 239: <P>
! 240: Separate functions are provided rather than using <b>pcre_malloc</b> and
! 241: <b>pcre_free</b> because the usage is very predictable: the block sizes
! 242: requested are always the same, and the blocks are always freed in reverse
! 243: order. A calling program might be able to implement optimized functions that
! 244: perform better than <b>malloc()</b> and <b>free()</b>. PCRE runs noticeably more
! 245: slowly when built in this way. This option affects only the <b>pcre_exec()</b>
! 246: function; it is not relevant for <b>pcre_dfa_exec()</b>.
! 247: </P>
! 248: <br><a name="SEC12" href="#TOC1">LIMITING PCRE RESOURCE USAGE</a><br>
! 249: <P>
! 250: Internally, PCRE has a function called <b>match()</b>, which it calls repeatedly
! 251: (sometimes recursively) when matching a pattern with the <b>pcre_exec()</b>
! 252: function. By controlling the maximum number of times this function may be
! 253: called during a single matching operation, a limit can be placed on the
! 254: resources used by a single call to <b>pcre_exec()</b>. The limit can be changed
! 255: at run time, as described in the
! 256: <a href="pcreapi.html"><b>pcreapi</b></a>
! 257: documentation. The default is 10 million, but this can be changed by adding a
! 258: setting such as
! 259: <pre>
! 260: --with-match-limit=500000
! 261: </pre>
! 262: to the <b>configure</b> command. This setting has no effect on the
! 263: <b>pcre_dfa_exec()</b> matching function.
! 264: </P>
! 265: <P>
! 266: In some environments it is desirable to limit the depth of recursive calls of
! 267: <b>match()</b> more strictly than the total number of calls, in order to
! 268: restrict the maximum amount of stack (or heap, if --disable-stack-for-recursion
! 269: is specified) that is used. A second limit controls this; it defaults to the
! 270: value that is set for --with-match-limit, which imposes no additional
! 271: constraints. However, you can set a lower limit by adding, for example,
! 272: <pre>
! 273: --with-match-limit-recursion=10000
! 274: </pre>
! 275: to the <b>configure</b> command. This value can also be overridden at run time.
! 276: </P>
! 277: <br><a name="SEC13" href="#TOC1">CREATING CHARACTER TABLES AT BUILD TIME</a><br>
! 278: <P>
! 279: PCRE uses fixed tables for processing characters whose code values are less
! 280: than 256. By default, PCRE is built with a set of tables that are distributed
! 281: in the file <i>pcre_chartables.c.dist</i>. These tables are for ASCII codes
! 282: only. If you add
! 283: <pre>
! 284: --enable-rebuild-chartables
! 285: </pre>
! 286: to the <b>configure</b> command, the distributed tables are no longer used.
! 287: Instead, a program called <b>dftables</b> is compiled and run. This outputs the
! 288: source for new set of tables, created in the default locale of your C runtime
! 289: system. (This method of replacing the tables does not work if you are cross
! 290: compiling, because <b>dftables</b> is run on the local host. If you need to
! 291: create alternative tables when cross compiling, you will have to do so "by
! 292: hand".)
! 293: </P>
! 294: <br><a name="SEC14" href="#TOC1">USING EBCDIC CODE</a><br>
! 295: <P>
! 296: PCRE assumes by default that it will run in an environment where the character
! 297: code is ASCII (or Unicode, which is a superset of ASCII). This is the case for
! 298: most computer operating systems. PCRE can, however, be compiled to run in an
! 299: EBCDIC environment by adding
! 300: <pre>
! 301: --enable-ebcdic
! 302: </pre>
! 303: to the <b>configure</b> command. This setting implies
! 304: --enable-rebuild-chartables. You should only use it if you know that you are in
! 305: an EBCDIC environment (for example, an IBM mainframe operating system). The
! 306: --enable-ebcdic option is incompatible with --enable-utf8.
! 307: </P>
! 308: <br><a name="SEC15" href="#TOC1">PCREGREP OPTIONS FOR COMPRESSED FILE SUPPORT</a><br>
! 309: <P>
! 310: By default, <b>pcregrep</b> reads all files as plain text. You can build it so
! 311: that it recognizes files whose names end in <b>.gz</b> or <b>.bz2</b>, and reads
! 312: them with <b>libz</b> or <b>libbz2</b>, respectively, by adding one or both of
! 313: <pre>
! 314: --enable-pcregrep-libz
! 315: --enable-pcregrep-libbz2
! 316: </pre>
! 317: to the <b>configure</b> command. These options naturally require that the
! 318: relevant libraries are installed on your system. Configuration will fail if
! 319: they are not.
! 320: </P>
! 321: <br><a name="SEC16" href="#TOC1">PCREGREP BUFFER SIZE</a><br>
! 322: <P>
! 323: <b>pcregrep</b> uses an internal buffer to hold a "window" on the file it is
! 324: scanning, in order to be able to output "before" and "after" lines when it
! 325: finds a match. The size of the buffer is controlled by a parameter whose
! 326: default value is 20K. The buffer itself is three times this size, but because
! 327: of the way it is used for holding "before" lines, the longest line that is
! 328: guaranteed to be processable is the parameter size. You can change the default
! 329: parameter value by adding, for example,
! 330: <pre>
! 331: --with-pcregrep-bufsize=50K
! 332: </pre>
! 333: to the <b>configure</b> command. The caller of \fPpcregrep\fP can, however,
! 334: override this value by specifying a run-time option.
! 335: </P>
! 336: <br><a name="SEC17" href="#TOC1">PCRETEST OPTION FOR LIBREADLINE SUPPORT</a><br>
! 337: <P>
! 338: If you add
! 339: <pre>
! 340: --enable-pcretest-libreadline
! 341: </pre>
! 342: to the <b>configure</b> command, <b>pcretest</b> is linked with the
! 343: <b>libreadline</b> library, and when its input is from a terminal, it reads it
! 344: using the <b>readline()</b> function. This provides line-editing and history
! 345: facilities. Note that <b>libreadline</b> is GPL-licensed, so if you distribute a
! 346: binary of <b>pcretest</b> linked in this way, there may be licensing issues.
! 347: </P>
! 348: <P>
! 349: Setting this option causes the <b>-lreadline</b> option to be added to the
! 350: <b>pcretest</b> build. In many operating environments with a sytem-installed
! 351: <b>libreadline</b> this is sufficient. However, in some environments (e.g.
! 352: if an unmodified distribution version of readline is in use), some extra
! 353: configuration may be necessary. The INSTALL file for <b>libreadline</b> says
! 354: this:
! 355: <pre>
! 356: "Readline uses the termcap functions, but does not link with the
! 357: termcap or curses library itself, allowing applications which link
! 358: with readline the to choose an appropriate library."
! 359: </pre>
! 360: If your environment has not been set up so that an appropriate library is
! 361: automatically included, you may need to add something like
! 362: <pre>
! 363: LIBS="-ncurses"
! 364: </pre>
! 365: immediately before the <b>configure</b> command.
! 366: </P>
! 367: <br><a name="SEC18" href="#TOC1">SEE ALSO</a><br>
! 368: <P>
! 369: <b>pcreapi</b>(3), <b>pcre_config</b>(3).
! 370: </P>
! 371: <br><a name="SEC19" href="#TOC1">AUTHOR</a><br>
! 372: <P>
! 373: Philip Hazel
! 374: <br>
! 375: University Computing Service
! 376: <br>
! 377: Cambridge CB2 3QH, England.
! 378: <br>
! 379: </P>
! 380: <br><a name="SEC20" href="#TOC1">REVISION</a><br>
! 381: <P>
! 382: Last updated: 06 September 2011
! 383: <br>
! 384: Copyright © 1997-2011 University of Cambridge.
! 385: <br>
! 386: <p>
! 387: Return to the <a href="index.html">PCRE index page</a>.
! 388: </p>
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