Tristan Matthews | 0461646 | 2013-11-14 16:09:34 -0500 | [diff] [blame] | 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> |
| 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> |