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diff --git a/external-libs/pcre/doc/pcrebuild.3 b/external-libs/pcre/doc/pcrebuild.3 deleted file mode 100644 index a91782c0..00000000 --- a/external-libs/pcre/doc/pcrebuild.3 +++ /dev/null @@ -1,145 +0,0 @@ -.TH PCRE 3 -.SH NAME -PCRE - Perl-compatible regular expressions -.SH PCRE BUILD-TIME OPTIONS -.rs -.sp -This document describes the optional features of PCRE that can be selected when -the library is compiled. They are all selected, or deselected, by providing -options to the \fBconfigure\fR script which is run before the \fBmake\fR -command. The complete list of options for \fBconfigure\fR (which includes the -standard ones such as the selection of the installation directory) can be -obtained by running - - ./configure --help - -The following sections describe certain options whose names begin with --enable -or --disable. These settings specify changes to the defaults for the -\fBconfigure\fR command. Because of the way that \fBconfigure\fR works, ---enable and --disable always come in pairs, so the complementary option always -exists as well, but as it specifies the default, it is not described. - -.SH UTF-8 SUPPORT -.rs -.sp -To build PCRE with support for UTF-8 character strings, add - - --enable-utf8 - -to the \fBconfigure\fR command. Of itself, this does not make PCRE treat -strings as UTF-8. As well as compiling PCRE with this option, you also have -have to set the PCRE_UTF8 option when you call the \fBpcre_compile()\fR -function. - -.SH CODE VALUE OF NEWLINE -.rs -.sp -By default, PCRE treats character 10 (linefeed) as the newline character. This -is the normal newline character on Unix-like systems. You can compile PCRE to -use character 13 (carriage return) instead by adding - - --enable-newline-is-cr - -to the \fBconfigure\fR command. For completeness there is also a ---enable-newline-is-lf option, which explicitly specifies linefeed as the -newline character. - -.SH BUILDING SHARED AND STATIC LIBRARIES -.rs -.sp -The PCRE building process uses \fBlibtool\fR to build both shared and static -Unix libraries by default. You can suppress one of these by adding one of - - --disable-shared - --disable-static - -to the \fBconfigure\fR command, as required. - -.SH POSIX MALLOC USAGE -.rs -.sp -When PCRE is called through the POSIX interface (see the \fBpcreposix\fR -documentation), additional working storage is required for holding the pointers -to capturing substrings because PCRE requires three integers per substring, -whereas the POSIX interface provides only two. If the number of expected -substrings is small, the wrapper function uses space on the stack, because this -is faster than using \fBmalloc()\fR for each call. The default threshold above -which the stack is no longer used is 10; it can be changed by adding a setting -such as - - --with-posix-malloc-threshold=20 - -to the \fBconfigure\fR command. - -.SH LIMITING PCRE RESOURCE USAGE -.rs -.sp -Internally, PCRE has a function called \fBmatch()\fR which it calls repeatedly -(possibly recursively) when performing a matching operation. By limiting the -number of times this function may be called, a limit can be placed on the -resources used by a single call to \fBpcre_exec()\fR. The limit can be changed -at run time, as described in the \fBpcreapi\fR documentation. The default is 10 -million, but this can be changed by adding a setting such as - - --with-match-limit=500000 - -to the \fBconfigure\fR command. - -.SH HANDLING VERY LARGE PATTERNS -.rs -.sp -Within a compiled pattern, offset values are used to point from one part to -another (for example, from an opening parenthesis to an alternation -metacharacter). By default two-byte values are used for these offsets, leading -to a maximum size for a compiled pattern of around 64K. This is sufficient to -handle all but the most gigantic patterns. Nevertheless, some people do want to -process enormous patterns, so it is possible to compile PCRE to use three-byte -or four-byte offsets by adding a setting such as - - --with-link-size=3 - -to the \fBconfigure\fR command. The value given must be 2, 3, or 4. Using -longer offsets slows down the operation of PCRE because it has to load -additional bytes when handling them. - -If you build PCRE with an increased link size, test 2 (and test 5 if you are -using UTF-8) will fail. Part of the output of these tests is a representation -of the compiled pattern, and this changes with the link size. - -.SH AVOIDING EXCESSIVE STACK USAGE -.rs -.sp -PCRE implements backtracking while matching by making recursive calls to an -internal function called \fBmatch()\fR. In environments where the size of the -stack is limited, this can severely limit PCRE's operation. (The Unix -environment does not usually suffer from this problem.) An alternative approach -that uses memory from the heap to remember data, instead of using recursive -function calls, has been implemented to work round this problem. If you want to -build a version of PCRE that works this way, add - - --disable-stack-for-recursion - -to the \fBconfigure\fR command. With this configuration, PCRE will use the -\fBpcre_stack_malloc\fR and \fBpcre_stack_free\fR variables to call memory -management functions. Separate functions are provided because the usage is very -predictable: the block sizes requested are always the same, and the blocks are -always freed in reverse order. A calling program might be able to implement -optimized functions that perform better than the standard \fBmalloc()\fR and -\fBfree()\fR functions. PCRE runs noticeably more slowly when built in this -way. - -.SH USING EBCDIC CODE -.rs -.sp -PCRE assumes by default that it will run in an environment where the character -code is ASCII (or UTF-8, which is a superset of ASCII). PCRE can, however, be -compiled to run in an EBCDIC environment by adding - - --enable-ebcdic - -to the \fBconfigure\fR command. - -.in 0 -Last updated: 09 December 2003 -.br -Copyright (c) 1997-2003 University of Cambridge. |