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| author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 12:06:34 +0000 |
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| committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 12:06:34 +0000 |
| commit | 5e61585d76ae77fd5e9e96ebabb57afa4d74880d (patch) | |
| tree | 2b467823aaeebc7ef8bc9e3cabe8074eaef1666d /proto/PCRE_README.html | |
| parent | Initial commit. (diff) | |
| download | postfix-5e61585d76ae77fd5e9e96ebabb57afa4d74880d.tar.xz postfix-5e61585d76ae77fd5e9e96ebabb57afa4d74880d.zip | |
Adding upstream version 3.5.24.upstream/3.5.24
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'proto/PCRE_README.html')
| -rw-r--r-- | proto/PCRE_README.html | 106 |
1 files changed, 106 insertions, 0 deletions
diff --git a/proto/PCRE_README.html b/proto/PCRE_README.html new file mode 100644 index 0000000..1f8059b --- /dev/null +++ b/proto/PCRE_README.html @@ -0,0 +1,106 @@ +<!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=us-ascii"> + +</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>Building Postfix with PCRE support</h2> + +<p> These instructions assume that you build Postfix from source +code as described in the INSTALL document. Some modification may +be required if you build Postfix from a vendor-specific source +package. </p> + +<p> Note: to use pcre with Debian GNU/Linux's Postfix, all you +need is to install the postfix-pcre package and you're done. There +is no need to recompile Postfix. </p> + +<p> In some future, Postfix will have a plug-in interface for adding +map types. Until then, you need to compile PCRE support into Postfix. +</p> + +<p> First of all, you need the PCRE library (Perl Compatible Regular +Expressions), which can be obtained from: </p> + +<blockquote> +ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/. +</blockquote> + +<p> NOTE: pcre versions prior to 2.06 cannot be used. </p> + +<p> In order to build Postfix with PCRE support you need to add +-DHAS_PCRE and a -I option for the PCRE include file to CCARGS, and +add the path to the PCRE library to AUXLIBS_PCRE, for example: </p> + +<blockquote> +<pre> +make -f Makefile.init makefiles \ + "CCARGS=-DHAS_PCRE `pcre-config --cflags`" \ + "AUXLIBS_PCRE=`pcre-config --libs`" +</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> |