Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages

  
 
  

home | help
REGEXP_TABLE(5)		      File Formats Manual	       REGEXP_TABLE(5)

NAME
       regexp_table - format of	Postfix	regular	expression tables

SYNOPSIS
       postmap -q "string" regexp:$config_directory/filename

       postmap -q - regexp:$config_directory/filename <inputfile

DESCRIPTION
       The  Postfix  mail  system  uses	optional tables	for address rewriting,
       mail routing, or	access control.	These tables are usually in dbm	or  db
       format.

       Alternatively,  lookup tables can be specified in POSIX regular expres-
       sion form. In this case,	each input is compared against a list of  pat-
       terns.  When a match is found, the corresponding	result is returned and
       the search is terminated.

       To find out what	types of lookup	tables your  Postfix  system  supports
       use the "postconf -m" command.

       To test lookup tables, use the "postmap -q" command as described	in the
       SYNOPSIS	 above.	 Use  "postmap -hmq - <file" for header_checks(5) pat-
       terns, and "postmap -bmq	- <file" for body_checks(5) (Postfix  2.6  and
       later).

COMPATIBILITY
       With  Postfix  version 2.2 and earlier specify "postmap -fq" to query a
       table that contains case	sensitive patterns. Patterns are case insensi-
       tive by default.

TABLE FORMAT
       The general form	of a Postfix regular expression	table is:

       /pattern/flags result
	      When pattern matches the input string, use the corresponding re-
	      sult value.

       !/pattern/flags result
	      When pattern does	not match the input  string,  use  the	corre-
	      sponding result value.

       if /pattern/flags

       endif  If  the  input  string  matches /pattern/, then match that input
	      string against the patterns between if and endif.	 The if..endif
	      can nest.

	      Note: do not prepend whitespace to patterns inside if..endif.

	      This feature is available	in Postfix 2.1 and later.

       if !/pattern/flags

       endif  If the input string does not match /pattern/,  then  match  that
	      input  string  against  the  patterns  between if	and endif. The
	      if..endif	can nest.

	      Note: do not prepend whitespace to patterns inside if..endif.

	      This feature is available	in Postfix 2.1 and later.

       blank lines and comments
	      Empty lines and whitespace-only lines are	ignored, as are	 lines
	      whose first non-whitespace character is a	`#'.

       multi-line text
	      A	 logical  line	starts	with  non-whitespace text. A line that
	      starts with whitespace continues a logical line.

       Each pattern is a POSIX regular expression enclosed by a	pair of	delim-
       iters. The regular expression syntax is documented in re_format(7) with
       4.4BSD, in regex(5) with	Solaris, and in	 regex(7)  with	 Linux.	 Other
       systems may use other document names.

       The  expression	delimiter can be any non-alphanumerical	character, ex-
       cept whitespace or characters that have special meaning	(traditionally
       the  forward  slash is used). The regular expression can	contain	white-
       space.

       By default, matching is case-insensitive, and newlines are not  treated
       as  special  characters.	The behavior is	controlled by flags, which are
       toggled by appending one	or more	of the following characters after  the
       pattern:

       i (default: on)
	      Toggles  the case	sensitivity flag. By default, matching is case
	      insensitive.

       m (default: off)
	      Toggle the multi-line mode flag. When this flag is on, the ^ and
	      $	metacharacters match immediately after and immediately	before
	      a	 newline  character,  respectively, in addition	to matching at
	      the start	and end	of the input string.

       x (default: on)
	      Toggles the extended expression syntax flag. By default, support
	      for extended expression syntax is	enabled.

TABLE SEARCH ORDER
       Patterns	are applied in the order as specified in the  table,  until  a
       pattern is found	that matches the input string.

       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  par-
       ent network search is done, and user@domain mail	addresses are not bro-
       ken  up	into  their user and domain constituent	parts, nor is user+foo
       broken up into user and foo.

TEXT SUBSTITUTION
       Substitution of substrings (text	that  matches  patterns	 inside	 "()")
       from  the  matched  expression into the result string is	requested with
       $1, $2, etc.; specify $$	to produce  a  $  character  as	 output.   The
       macros  in  the result string may need to be written as ${n} or $(n) if
       they aren't followed by whitespace.

       Note: since negated patterns (those preceded by !) return a result when
       the expression does not match,  substitutions  are  not	available  for
       negated patterns.

INLINE SPECIFICATION
       The contents of a table may be specified	in the table name (Postfix 3.7
       and later).  The	basic syntax is:

       main.cf:
	   parameter = .. regexp:{ { rule-1 }, { rule-2	} .. } ..

       master.cf:
	   .. -o { parameter = .. regexp:{ { rule-1 }, { rule-2	} .. } .. } ..

       Postfix	recursively  expands any $parametername	instances in the above
       parameter value,	ignores	whitespace  after  '{'	and  before  '}',  and
       writes each rule	as one text line to an in-memory file:

       in-memory file:
	   rule-1
	   rule-2
	   ..

       Postfix parses the result as if it is a file in /usr/local/etc/postfix.

INLINE SPECIFICATION CAVEATS
             Avoid  using  $parametername  inside an inlined regexp: pattern.
	      The  pattern  would  have	 unexpected  matches  when  there  are
	      metacharacters  such  as '.' in the $parametername expansion. To
	      prevent unexpected matches,  use	a  pcre:  table,  and  specify
	      \Q$parametername\E.

             When  an inlined rule must contain $, specify $$ to keep Postfix
	      from trying to do	$name expansion	as it  evaluates  a  parameter
	      value.  To  check	an inline configuration, use the "postconf -x"
	      option as	shown below:

	      	     When a main.cf "parametername =  value" setting  contains
		     an	inline regexp: table, use the command "postconf	-x pa-
		     rametername". Verify that there are no "undefined parame-
		     ter"  warnings,  and  that	the output has the syntax that
		     one would use in a	non-inlined Postfix regexp: file.

	      	     When a master.cf "-o { parametername = value }"  override
		     contains  an inline regexp: table,	use the	command	"post-
		     conf -Px '*/*/parametername' ". Verify that there are  no
		     "undefined	 parameter"  warnings, and that	the output has
		     the syntax	that one would use in  a  non-inlined  Postfix
		     regexp: file.

EXAMPLE	SMTPD ACCESS MAP
       # Disallow sender-specified routing. This is a must if you relay	mail
       # for other domains.
       /[%!@].*[%!@]/	    550	Sender-specified routing rejected

       # Postmaster is OK, that	way they can talk to us	about how to fix
       # their problem.
       /^postmaster@/	    OK

       # Protect your outgoing majordomo exploders
       if !/^owner-/
       /^(.*)-outgoing@(.*)$/  550 Use ${1}@${2} instead
       endif

EXAMPLE	HEADER FILTER MAP
       # These were once common	in junk	mail.
       /^Subject: make money fast/     REJECT
       /^To: friend@public\.com/       REJECT

EXAMPLE	BODY FILTER MAP
       # First skip over base 64 encoded text to save CPU cycles.
       ~^[[:alnum:]+/]{60,}$~	       OK

       # Put your own body patterns here.

SEE ALSO
       postmap(1), Postfix lookup table	manager
       pcre_table(5), format of	PCRE tables
       cidr_table(5), format of	CIDR tables

README FILES
       Use  "postconf readme_directory"	or "postconf html_directory" to	locate
       this information.
       DATABASE_README,	Postfix	lookup table overview

AUTHOR(S)
       The regexp table	lookup code was	originally written by:
       LaMont Jones
       lamont@hp.com

       That code was based on the PCRE dictionary contributed by:
       Andrew McNamara
       andrewm@connect.com.au
       connect.com.au Pty. Ltd.
       Level 3,	213 Miller St
       North Sydney, NSW, Australia

       Adopted and adapted by:
       Wietse Venema
       IBM T.J.	Watson Research
       P.O. Box	704
       Yorktown	Heights, NY 10598, USA

       Wietse Venema
       Google, Inc.
       111 8th Avenue
       New York, NY 10011, USA

							       REGEXP_TABLE(5)

Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=regexp_table&sektion=5&manpath=FreeBSD+Ports+14.3.quarterly>

home | help