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| author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 16:18:56 +0000 |
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| committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 16:18:56 +0000 |
| commit | b7c15c31519dc44c1f691e0466badd556ffe9423 (patch) | |
| tree | f944572f288bab482a615e09af627d9a2b6727d8 /proto/PCRE_README.html | |
| parent | Initial commit. (diff) | |
| download | postfix-b7c15c31519dc44c1f691e0466badd556ffe9423.tar.xz postfix-b7c15c31519dc44c1f691e0466badd556ffe9423.zip | |
Adding upstream version 3.7.10.upstream/3.7.10upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'proto/PCRE_README.html')
| -rw-r--r-- | proto/PCRE_README.html | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/proto/PCRE_README.html b/proto/PCRE_README.html new file mode 100644 index 0000000..1741826 --- /dev/null +++ b/proto/PCRE_README.html @@ -0,0 +1,123 @@ +<!doctype html public "-//W3C//DTD HTML 4.01 Transitional//EN" + "http://www.w3.org/TR/html4/loose.dtd"> + +<html> + +<head> + +<title>Postfix PCRE Support</title> + +<meta http-equiv="Content-Type" content="text/html; charset=utf-8"> + +</head> + +<body> + +<h1><img src="postfix-logo.jpg" width="203" height="98" ALT="">Postfix PCRE Support</h1> + +<hr> + +<h2>PCRE (Perl Compatible Regular Expressions) map support</h2> + +<p> The optional "pcre" map type allows you to specify regular +expressions with the PERL style notation such as \s for space and +\S for non-space. The main benefit, however, is that pcre lookups +are often faster than regexp lookups. This is because the pcre +implementation is often more efficient than the POSIX regular +expression implementation that you find on many systems. </p> + +<p> A description of how to use pcre tables, including examples, +is given in the pcre_table(5) manual page. Information about PCRE +itself can be found at http://www.pcre.org/. </p> + +<h2>Using Postfix packages with PCRE support</h2> + +<p> To use pcre with Debian GNU/Linux's Postfix, or with Fedora or +RHEL Postfix, all you +need is to install the postfix-pcre package and you're done. There +is no need to recompile Postfix. </p> + +<h2>Building Postfix from source with PCRE support</h2> + +<p> These instructions assume that you build Postfix from source +code as described in the INSTALL document. </p> + +<p> To build Postfix from source with pcre support, you need a pcre +library. Install a vendor package, or download the source code from +locations in https://www.pcre.org/ and build that yourself. + +<p> Postfix can build with the pcre2 library or the legacy pcre +library. It's probably easiest to let the Postfix build procedure +pick one. The following commands will first discover if the pcre2 +library is installed, and if that is not available, will discover +if the legacy pcre library is installed. </p> + +<blockquote> +<pre> +$ make -f Makefile.init makefiles +$ make +</pre> +</blockquote> + +<p> To build Postfix explicitly with a pcre2 library (Postfix 3.7 +and later): </p> + +<blockquote> +<pre> +$ make -f Makefile.init makefiles \ + "CCARGS=-DHAS_PCRE=2 `pcre2-config --cflags`" \ + "AUXLIBS_PCRE=`pcre2-config --libs8`" +$ make +</pre> +</blockquote> + +<p> To build Postfix explicitly with a legacy pcre library (all +Postfix versions): </p> + +<blockquote> +<pre> +$ make -f Makefile.init makefiles \ + "CCARGS=-DHAS_PCRE=1 `pcre-config --cflags`" \ + "AUXLIBS_PCRE=`pcre-config --libs`" +$ make +</pre> +</blockquote> + +<p> Postfix versions before 3.0 use AUXLIBS instead of AUXLIBS_PCRE. +With Postfix 3.0 and later, the old AUXLIBS variable still supports +building a statically-loaded PCRE database client, but only the new +AUXLIBS_PCRE variable supports building a dynamically-loaded or +statically-loaded PCRE database client. </p> + +<blockquote> + +<p> Failure to use the AUXLIBS_PCRE variable will defeat the purpose +of dynamic database client loading. Every Postfix executable file +will have PCRE library dependencies. And that was exactly +what dynamic database client loading was meant to avoid. </p> + +</blockquote> + +<h2>Things to know</h2> + +<ul> + +<li> <p> When Postfix searches a pcre: or regexp: lookup table, +each pattern is applied to the entire input string. Depending on +the application, that string is an entire client hostname, an entire +client IP address, or an entire mail address. Thus, no parent domain +or parent network search is done, "user@domain" mail addresses are +not broken up into their user and domain constituent parts, and +"user+foo" is not broken up into user and foo. </p> + +<li> <p> Regular expression tables such as pcre: or regexp: are +not allowed to do $number substitution in lookup results that can +be security sensitive: currently, that restriction applies to the +local aliases(5) database or the virtual(8) delivery agent tables. +</p> + +</ul> + +</body> + +</html> |