-Privoxy uses the Perl Compatible Regular Expressions (PCRE) library when matching its rules against the folder-and-file part of a target URL. Privoxy ships with a bundled PCRE library that, whilst convenient, is very out of date (version 3). The recommendation is therefore to download, make and install the latest PCRE distribution to your build machine and compile Privoxy against that instead.
+Privoxy uses the Perl Compatible Regular Expressions (PCRE) library when matching its rules against the folder-and-file part of a target URL. Privoxy's source ships with a version of the PCRE library that, whilst convenient, is very out of date (version 3). The recommendation is therefore to download, make and install the latest PCRE distribution to your build machine and compile Privoxy against that instead.
+
+To support this, build.sh takes an optional second parameter (-pcre) which tells it to look for an installation of the PCRE library in the standard location on the build machine (/usr/local/lib). The obvious corrollary is that you must have downloaded, configured, made and installed PCRE before building Privoxy if you wish to link to the external library.
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+There are two important further considerations that this approach brings. Firstly, you must ensure when building PCRE that you build it to support the same minimum version of OS X that you wish Privoxy to support (note that by default PCRE's build process assumes the OS X version of the build machine is the minimum version to be supported). Failure to match the minimum supported versions will mean that, whilst Privoxy will still build, the external PCRE check will fail and you will end up compiling in the bundled PCRE, not linking to the external PCRE library as you'd intended.
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+The second consideration when using external PCRE is that the PCRE build process allows only single-architecture libraries to be built, which means that the Privoxy binary you build must also be single-architecture. The outcome of not following this rule would be as above; you will succeed in building Privoxy but it will compile in the bundled PCRE rather than linking to the external library.
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+A sample command line for building Privoxy with external PCRE to run on Snow Leopard and higher on 64 bit Intel Macs is:
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+./build.sh snowleopardx64 -pcre
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+
+1.2 Builds for the Sourceforge Privoxy project release set