From b5896ba9f6047e7031e2bdee0622d543e11a6734 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Mon, 6 May 2024 03:46:30 +0200 Subject: Adding upstream version 3.4.23. Signed-off-by: Daniel Baumann --- proto/PCRE_README.html | 106 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 106 insertions(+) create mode 100644 proto/PCRE_README.html (limited to 'proto/PCRE_README.html') 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 @@ + + + + + + +Postfix PCRE Support + + + + + + + +

Postfix PCRE Support

+ +

PCRE (Perl Compatible Regular Expressions) map support

+ +

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.

+ +

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/.

+ +

Building Postfix with PCRE support

+ +

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.

+ +

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.

+ +

In some future, Postfix will have a plug-in interface for adding +map types. Until then, you need to compile PCRE support into Postfix. +

+ +

First of all, you need the PCRE library (Perl Compatible Regular +Expressions), which can be obtained from:

+ +

+ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/. +

+ +

NOTE: pcre versions prior to 2.06 cannot be used.

+ +

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:

+ +

+make -f Makefile.init makefiles \
+    "CCARGS=-DHAS_PCRE `pcre-config --cflags`" \
+    "AUXLIBS_PCRE=`pcre-config --libs`"
+

+ +

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.

+ +

+ +
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.
+ +

+ +

Things to know

+ +

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.
+ +
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. +
+ +

+ + + + -- cgit v1.2.3