# PCRE_TABLE(5) PCRE_TABLE(5)
#
# NAME
# pcre_table - format of Postfix PCRE tables
#
# SYNOPSIS
# pcre:/etc/postfix/filename
#
# postmap -q "string" pcre:/etc/postfix/filename
#
# postmap -q - pcre:/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 Perl Compatible 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 PCRE table is:
#
# /pattern/flags result
# When pattern matches a search string, use the cor-
# responding 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
#
# endif Examine the lines between if..endif only if pattern
# matches. The if..endif can nest. Do not prepend
# whitespace to patterns inside if..endif.
#
# Each pattern is a perl-like regular expression. The
# expression delimiter can be any character, except whites-
# pace or characters that have special meaning (tradition-
# ally the forward slash is used). The regular expression
# can contain whitespace.
#
# By default, matching is case-insensitive, and newlines are
# not treated as special characters. The behavior is con-
# trolled 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)
# Toggles the PCRE_MULTILINE 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 subject string.
#
# s (default: on)
# Toggles the PCRE_DOTALL flag. When this flag is on,
# the . metacharacter matches the newline character.
# With Postfix versions prior to 20020528, The flag
# is off by default, which is inconvenient for multi-
# line message header matching.
#
# x (default: off)
# Toggles the pcre extended flag. When this flag is
# on, whitespace in the pattern (other than in a
# character class) and characters between a # outside
# a character class and the next newline character
# are ignored. An escaping backslash can be used to
# include a whitespace or # character as part of the
# pattern.
#
# A (default: off)
# Toggles the PCRE_ANCHORED flag. When this flag is
# on, the pattern is forced to be "anchored", that
# is, it is constrained to match only at the start of
# the string which is being searched (the "subject
# string"). This effect can also be achieved by
# appropriate constructs in the pattern itself.
#
# E (default: off)
# Toggles the PCRE_DOLLAR_ENDONLY flag. When this
# flag is on, a $ metacharacter in the pattern
# matches only at the end of the subject string.
# Without this flag, a dollar also matches immedi-
# ately before the final character if it is a newline
# character (but not before any other newline charac-
# ters). This flag is ignored if PCRE_MULTILINE flag
# is set.
#
# U (default: off)
# Toggles the ungreedy matching flag. When this flag
# is on, the pattern matching engine inverts the
# "greediness" of the quantifiers so that they are
# not greedy by default, but become greedy if fol-
# lowed by "?". This flag can also set by a (?U)
# modifier within the pattern.
#
# X (default: off)
# Toggles the PCRE_EXTRA flag. When this flag is on,
# any backslash in a pattern that is followed by a
# letter that has no special meaning causes an error,
# thus reserving these combinations for future expan-
# sion.
#
# 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 the conventional
# perl syntax ($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
# # Protect your outgoing majordomo exploders
# /^(?!owner-)(.*)-outgoing@(.*)/ 550 Use ${1}@${2} instead
#
# # Bounce friend@whatever, except when whatever is our domain (you would
# # be better just bouncing all friend@ mail - this is just an example).
# /^friend@(?!my\.domain)/ 550 Stick this in your pipe $0
#
# # A multi-line entry. The text is sent as one line.
# #
# /^noddy@my\.domain$/
# 550 This user is a funny one. You really don't want to send mail to
# them as it only makes their head spin.
#
# EXAMPLE HEADER FILTER MAP
# /^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.
# # Requires PCRE version 3.
# ~^[[:alnum:]+/]{60,}$~ OK
#
# # Put your own body patterns here.
#
# SEE ALSO
# regexp_table(5) format of POSIX regular expression tables
#
# AUTHOR(S)
# The PCRE table lookup code was originally written 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
#
# PCRE_TABLE(5)