#++
# NAME
# pcre_table 5
# SUMMARY
# format of Postfix PCRE tables
# SYNOPSIS
# \fBpostmap -q "\fIstring\fB" pcre:/etc/postfix/\fIfilename\fR
#
# \fBpostmap -q - pcre:/etc/postfix/\fIfilename\fR <\fIinputfile\fR
# DESCRIPTION
# The Postfix mail system uses optional tables for address
# rewriting, mail routing, or access control. These tables
# are usually in \fBdbm\fR or \fBdb\fR format.
#
# Alternatively, lookup tables can be specified in Perl Compatible
# 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 "\fBpostconf -m\fR" command.
#
# To test lookup tables, use the "\fBpostmap -q\fR" command as
# described in the SYNOPSIS above.
# COMPATIBILITY
# .ad
# .fi
# With Postfix version 2.2 and earlier specify "\fBpostmap
# -fq\fR" to query a table that contains case sensitive
# patterns. Patterns are case insensitive by default.
# TABLE FORMAT
# .ad
# .fi
# The general form of a PCRE table is:
# .IP "\fB/\fIpattern\fB/\fIflags result\fR"
# When \fIpattern\fR matches the input string, use
# the corresponding \fIresult\fR value.
# .IP "\fB!/\fIpattern\fB/\fIflags result\fR"
# When \fIpattern\fR does \fBnot\fR match the input string, use
# the corresponding \fIresult\fR value.
# .IP "\fBif /\fIpattern\fB/\fIflags\fR"
# .IP "\fBendif\fR"
# Match the input string against the patterns between \fBif\fR
# and \fBendif\fR, if and only if that same input string also matches
# \fIpattern\fR. The \fBif\fR..\fBendif\fR can nest.
# .sp
# Note: do not prepend whitespace to patterns inside
# \fBif\fR..\fBendif\fR.
# .sp
# This feature is available in Postfix 2.1 and later.
# .IP "\fBif !/\fIpattern\fB/\fIflags\fR"
# .IP "\fBendif\fR"
# Match the input string against the patterns between \fBif\fR
# and \fBendif\fR, if and only if that same input string does \fBnot\fR
# match \fIpattern\fR. The \fBif\fR..\fBendif\fR can nest.
# .sp
# Note: do not prepend whitespace to patterns inside
# \fBif\fR..\fBendif\fR.
# .sp
# This feature is available in Postfix 2.1 and later.
# .IP "blank lines and comments"
# Empty lines and whitespace-only lines are ignored, as
# are lines whose first non-whitespace character is a `#'.
# .IP "multi-line text"
# A logical line starts with non-whitespace text. A line that
# starts with whitespace continues a logical line.
# .PP
# Each pattern is a perl-like regular expression. The expression
# delimiter can be any non-alphanumerical character, 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, 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:
# .IP "\fBi\fR (default: on)"
# Toggles the case sensitivity flag. By default, matching is case
# insensitive.
# .IP "\fBm\fR (default: off)"
# Toggles the PCRE_MULTILINE flag. When this flag is on, the \fB^\fR
# and \fB$\fR metacharacters match immediately after and immediately
# before a newline character, respectively, in addition to
# matching at the start and end of the subject string.
# .IP "\fBs\fR (default: on)"
# Toggles the PCRE_DOTALL flag. When this flag is on, the \fB.\fR
# metacharacter matches the newline character. With
# Postfix versions prior to 2.0, the flag is off by
# default, which is inconvenient for multi-line message header
# matching.
# .IP "\fBx\fR (default: off)"
# Toggles the pcre extended flag. When this flag is on, whitespace
# characters in the pattern (other than in a character class)
# are ignored. To include a whitespace character as part of
# the pattern, escape it with backslash.
# .sp
# Note: do not use \fB#\fIcomment\fR after patterns.
# .IP "\fBA\fR (default: off)"
# Toggles the PCRE_ANCHORED flag. When this flag is on,
# the pattern is forced to be "anchored", that is, it is
# constrained to match only at the start of the string which
# is being searched (the "subject string"). This effect can
# also be achieved by appropriate constructs in the pattern
# itself.
# .IP "\fBE\fR (default: off)"
# Toggles the PCRE_DOLLAR_ENDONLY flag. When this flag is on,
# a \fB$\fR metacharacter in the pattern matches only at the
# end of the subject string. Without this flag, a dollar also
# matches immediately before the final character if it is a
# newline character (but not before any other newline
# characters). This flag is ignored if PCRE_MULTILINE
# flag is set.
# .IP "\fBU\fR (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 followed by "?". This flag can also
# set by a (?U) modifier within the pattern.
# .IP "\fBX\fR (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 expansion.
# SEARCH ORDER
# .ad
# .fi
# 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
# \fIuser@domain\fR mail addresses are not broken up into their
# \fIuser\fR and \fIdomain\fR constituent parts, nor is \fIuser+foo\fR
# broken up into \fIuser\fR and \fIfoo\fR.
# TEXT SUBSTITUTION
# .ad
# .fi
# Substitution of substrings from the matched expression into the result
# string is possible using the conventional perl syntax ($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 \fB!\fR) return a
# result when the expression does not match, substitutions are not
# available for negated patterns.
# 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 $1
#
# # A multi-line entry. The text is sent as one line.
# #
# /^noddy@my\\.domain$/
# \ 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
# postmap(1), Postfix lookup table manager
# postconf(5), configuration parameters
# regexp_table(5), format of POSIX regular expression tables
# README FILES
# .ad
# .fi
# Use "\fBpostconf readme_directory\fR" or
# "\fBpostconf html_directory\fR" to locate this information.
# .na
# .nf
# DATABASE_README, Postfix lookup table overview
# 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
#--