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5 <title> Postfix manual - pcre_table(
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7 PCRE_TABLE(
5) PCRE_TABLE(
5)
10 pcre_table - format of Postfix PCRE tables
13 <b>postmap -q
"</b><i>string</i><b>" <a href=
"pcre_table.5.html">pcre
</a>:/etc/postfix/
</b><i>filename
</i>
15 <b>postmap -q -
<a href=
"pcre_table.5.html">pcre
</a>:/etc/postfix/
</b><i>filename
</i> <<i>inputfile
</i>
18 The Postfix mail system uses optional tables for address
19 rewriting, mail routing, or access control. These tables
20 are usually in
<b>dbm
</b> or
<b>db
</b> format.
22 Alternatively, lookup tables can be specified in Perl Com-
23 patible Regular Expression form. In this case, each input
24 is compared against a list of patterns. When a match is
25 found, the corresponding result is returned and the search
28 To find out what types of lookup tables your Postfix sys-
29 tem supports use the
"<b>postconf -m</b>" command.
31 To test lookup tables, use the
"<b>postmap -q</b>" command as
32 described in the SYNOPSIS above.
35 With Postfix version
2.2 and earlier specify
"<b>postmap -fq</b>"
36 to query a table that contains case sensitive patterns.
37 Patterns are case insensitive by default.
40 The general form of a PCRE table is:
42 <b>/
</b><i>pattern
</i><b>/
</b><i>flags result
</i>
43 When
<i>pattern
</i> matches the input string, use the cor-
44 responding
<i>result
</i> value.
46 <b>!/
</b><i>pattern
</i><b>/
</b><i>flags result
</i>
47 When
<i>pattern
</i> does
<b>not
</b> match the input string, use
48 the corresponding
<i>result
</i> value.
50 <b>if /
</b><i>pattern
</i><b>/
</b><i>flags
</i>
52 <b>endif
</b> Match the input string against the patterns between
53 <b>if
</b> and
<b>endif
</b>, if and only if that same input string
54 also matches
<i>pattern
</i>. The
<b>if
</b>..
<b>endif
</b> can nest.
56 Note: do not prepend whitespace to patterns inside
57 <b>if
</b>..
<b>endif
</b>.
59 This feature is available in Postfix
2.1 and later.
61 <b>if !/
</b><i>pattern
</i><b>/
</b><i>flags
</i>
63 <b>endif
</b> Match the input string against the patterns between
64 <b>if
</b> and
<b>endif
</b>, if and only if that same input string
65 does
<b>not
</b> match
<i>pattern
</i>. The
<b>if
</b>..
<b>endif
</b> can nest.
67 Note: do not prepend whitespace to patterns inside
68 <b>if
</b>..
<b>endif
</b>.
70 This feature is available in Postfix
2.1 and later.
72 blank lines and comments
73 Empty lines and whitespace-only lines are ignored,
74 as are lines whose first non-whitespace character
78 A logical line starts with non-whitespace text. A
79 line that starts with whitespace continues a logi-
82 Each pattern is a perl-like regular expression. The
83 expression delimiter can be any non-alphanumerical charac-
84 ter, except whitespace or characters that have special
85 meaning (traditionally the forward slash is used). The
86 regular expression can contain whitespace.
88 By default, matching is case-insensitive, and newlines are
89 not treated as special characters. The behavior is con-
90 trolled by flags, which are toggled by appending one or
91 more of the following characters after the pattern:
93 <b>i
</b> (default: on)
94 Toggles the case sensitivity flag. By default,
95 matching is case insensitive.
97 <b>m
</b> (default: off)
98 Toggles the PCRE_MULTILINE flag. When this flag is
99 on, the
<b>^
</b> and
<b>$
</b> metacharacters match immediately
100 after and immediately before a newline character,
101 respectively, in addition to matching at the start
102 and end of the subject string.
104 <b>s
</b> (default: on)
105 Toggles the PCRE_DOTALL flag. When this flag is on,
106 the
<b>.
</b> metacharacter matches the newline character.
107 With Postfix versions prior to
2.0, the flag is off
108 by default, which is inconvenient for multi-line
109 message header matching.
111 <b>x
</b> (default: off)
112 Toggles the pcre extended flag. When this flag is
113 on, whitespace characters in the pattern (other
114 than in a character class) are ignored. To include
115 a whitespace character as part of the pattern,
116 escape it with backslash.
118 Note: do not use
<b>#
</b><i>comment
</i> after patterns.
120 <b>A
</b> (default: off)
121 Toggles the PCRE_ANCHORED flag. When this flag is
122 on, the pattern is forced to be
"anchored", that
123 is, it is constrained to match only at the start of
124 the string which is being searched (the
"subject
125 string"). This effect can also be achieved by
126 appropriate constructs in the pattern itself.
128 <b>E
</b> (default: off)
129 Toggles the PCRE_DOLLAR_ENDONLY flag. When this
130 flag is on, a
<b>$
</b> metacharacter in the pattern
131 matches only at the end of the subject string.
132 Without this flag, a dollar also matches immedi-
133 ately before the final character if it is a newline
134 character (but not before any other newline charac-
135 ters). This flag is ignored if PCRE_MULTILINE flag
138 <b>U
</b> (default: off)
139 Toggles the ungreedy matching flag. When this flag
140 is on, the pattern matching engine inverts the
141 "greediness" of the quantifiers so that they are
142 not greedy by default, but become greedy if fol-
143 lowed by
"?". This flag can also set by a (?U)
144 modifier within the pattern.
146 <b>X
</b> (default: off)
147 Toggles the PCRE_EXTRA flag. When this flag is on,
148 any backslash in a pattern that is followed by a
149 letter that has no special meaning causes an error,
150 thus reserving these combinations for future expan-
154 Patterns are applied in the order as specified in the ta-
155 ble, until a pattern is found that matches the input
158 Each pattern is applied to the entire input string.
159 Depending on the application, that string is an entire
160 client hostname, an entire client IP address, or an entire
161 mail address. Thus, no parent domain or parent network
162 search is done, and
<i>user@domain
</i> mail addresses are not
163 broken up into their
<i>user
</i> and
<i>domain
</i> constituent parts,
164 nor is
<i>user+foo
</i> broken up into
<i>user
</i> and
<i>foo
</i>.
166 <b>TEXT SUBSTITUTION
</b>
167 Substitution of substrings from the matched expression
168 into the result string is possible using the conventional
169 perl syntax ($
1, $
2, etc.); specify $$ to produce a $
170 character as output. The macros in the result string may
171 need to be written as ${n} or $(n) if they aren't followed
174 Note: since negated patterns (those preceded by
<b>!
</b>) return
175 a result when the expression does not match, substitutions
176 are not available for negated patterns.
178 <b>EXAMPLE SMTPD ACCESS MAP
</b>
179 # Protect your outgoing majordomo exploders
180 /^(?!owner-)(.*)-outgoing@(.*)/
550 Use ${
1}@${
2} instead
182 # Bounce friend@whatever, except when whatever is our domain (you would
183 # be better just bouncing all friend@ mail - this is just an example).
184 /^(friend@(?!my\.domain$).*)$/
550 Stick this in your pipe $
1
186 # A multi-line entry. The text is sent as one line.
189 550 This user is a funny one. You really don't want to send mail to
190 them as it only makes their head spin.
192 <b>EXAMPLE HEADER FILTER MAP
</b>
193 /^Subject: make money fast/ REJECT
194 /^To: friend@public\.com/ REJECT
196 <b>EXAMPLE BODY FILTER MAP
</b>
197 # First skip over base
64 encoded text to save CPU cycles.
198 # Requires PCRE version
3.
199 ~^[[:alnum:]+/]{
60,}$~ OK
201 # Put your own body patterns here.
204 <a href=
"postmap.1.html">postmap(
1)
</a>, Postfix lookup table manager
205 <a href=
"postconf.5.html">postconf(
5)
</a>, configuration parameters
206 <a href=
"regexp_table.5.html">regexp_table(
5)
</a>, format of POSIX regular expression tables
209 <a href=
"DATABASE_README.html">DATABASE_README
</a>, Postfix lookup table overview
212 The PCRE table lookup code was originally written by:
214 andrewm@connect.com.au
215 connect.com.au Pty. Ltd.
216 Level
3,
213 Miller St
217 North Sydney, NSW, Australia
219 Adopted and adapted by:
221 IBM T.J. Watson Research
223 Yorktown Heights, NY
10598, USA
226 </pre> </body> </html>