# REGEXP_TABLE(5) REGEXP_TABLE(5)
#
# NAME
# regexp_table - format of Postfix regular expression tables
#
# SYNOPSIS
# regexp:/etc/postfix/filename
#
# 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 or mail routing. These tables are usually in dbm
# or db format. Alternatively, lookup tables can be speci-
# fied in POSIX regular expression form.
#
# To find out what types of lookup tables your Postfix sys-
# tem supports use the postconf -m command.
#
# To test lookup tables, use the postmap command as
# described in the SYNOPSIS above.
#
# The general form of a Postfix regular expression table is:
#
# /pattern/flags result
#
# !/pattern/flags result
# When pattern matches (does not match) a search
# string, use the corresponding result value.
#
# 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 logi-
# cal line.
#
# if /pattern/flags
#
# if !/pattern/flags
#
# endif Examine the lines between if..endif only if pattern
# matches (does not match). The if..endif can nest.
# Do not prepend whitespace to patterns inside
# if..endif.
#
# Each pattern is a regular expression enclosed by a pair of
# delimiters. The regular expression syntax is described in
# re_format(7). The expression delimiter can be any charac-
# ter, except whitespace or characters that have special
# meaning (traditionally the forward slash is used). The
# regular expression can contain whitespace.
#
# By default, matching is case-insensitive, although follow-
# ing the second slash with an `i' flag will reverse this.
# Other flags are `x' (disable extended expression syntax),
# and `m' (enable multi-line mode, that is, treat newline
# characters as special).
#
# Each pattern is applied to the entire lookup key 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.
#
# Patterns are applied in the order as specified in the
# table, until a pattern is found that matches the search
# string.
#
# Substitution of substrings from the matched expression
# into the result string is possible using $1, $2, etc.. The
# macros in the result string may need to be written as ${n}
# or $(n) if they aren't followed by whitespace.
#
# EXAMPLE SMTPD ACCESS MAP
# # Disallow sender-specified routing. This is a must if you relay mail
# # for other domains.
# /[%!@].*[%!@]/ 550 Sender-specified routing rejected
#
# # Postmaster is OK, that way they can talk to us about how to fix
# # their problem.
# /^postmaster@/ OK
#
# # Protect your outgoing majordomo exploders
# if !/^owner-/
# /^(.*)-outgoing@(.*)$/ 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
# pcre_table(5) format of PCRE tables
#
# 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
#
# REGEXP_TABLE(5)