phpman > man > regexp_table(5)

REGEXP_TABLE(5)                          File Formats Manual                         REGEXP_TABLE(5)



NAME
       regexp_table - format of Postfix regular expression tables

SYNOPSIS
       postmap -q "string" regexp:/etc/postfix/filename

       postmap -q - regexp:/etc/postfix/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 expression form. In this case,
       each  input  is compared against a list of patterns. 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)  patterns,  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 insensitive 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 result value.

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

       if /pattern/flags

       endif  If the input string matches /pattern/, then match that input string against  the  pat‐
              terns 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-white‐
              space 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 delimiters. The regular  ex‐
       pression  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, except whitespace or  char‐
       acters  that  have special meaning (traditionally the forward slash is used). The regular ex‐
       pression can contain whitespace.

       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 fol‐
       lowing 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  expres‐
              sion 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 parent network search is done, and user@domain mail  addresses  are
       not  broken  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  expres‐
       sion into the result string is requested with $1, $2, etc.; specify $$ to produce a $ charac‐
       ter 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.

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 AT hp.com

       That code was based on the PCRE dictionary contributed by:
       Andrew McNamara
       andrewm AT connect.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)