summaryrefslogtreecommitdiffstats
path: root/html/pcre_table.5.html
blob: f2ee70ac0248324b6b36bc570ed5a8eeb74b1760 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
<!doctype html public "-//W3C//DTD HTML 4.01 Transitional//EN"
        "http://www.w3.org/TR/html4/loose.dtd">
<html> <head>
<meta http-equiv="Content-Type" content="text/html; charset=us-ascii">
<title> Postfix manual - pcre_table(5) </title>
</head> <body> <pre>
PCRE_TABLE(5)                                                    PCRE_TABLE(5)

<b>NAME</b>
       pcre_table - format of Postfix PCRE tables

<b>SYNOPSIS</b>
       <b>postmap -q "</b><i>string</i><b>" <a href="pcre_table.5.html">pcre</a>:/etc/postfix/</b><i>filename</i>

       <b>postmap -q - <a href="pcre_table.5.html">pcre</a>:/etc/postfix/</b><i>filename</i> &lt;<i>inputfile</i>

       <b>postmap -hmq - <a href="pcre_table.5.html">pcre</a>:/etc/postfix/</b><i>filename</i> &lt;<i>inputfile</i>

       <b>postmap -bmq - <a href="pcre_table.5.html">pcre</a>:/etc/postfix/</b><i>filename</i> &lt;<i>inputfile</i>

<b>DESCRIPTION</b>
       The  Postfix  mail  system  uses optional tables for address rewriting,
       mail routing, or access control. These tables are usually in <b>dbm</b> or  <b>db</b>
       format.

       Alternatively,  lookup tables can be specified in Perl Compatible Regu-
       lar 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 "<b>postconf -m</b>" command.

       To test lookup tables, use the "<b>postmap -q</b>" command as described in the
       SYNOPSIS above. Use "<b>postmap -hmq -</b> &lt;<i>file</i>"  for  <a href="header_checks.5.html">header_checks(5)</a>  pat-
       terns,  and  "<b>postmap -bmq -</b> &lt;<i>file</i>" for <a href="header_checks.5.html">body_checks(5)</a> (Postfix 2.6 and
       later).

<b>COMPATIBILITY</b>
       With Postfix version 2.2 and earlier specify "<b>postmap -fq</b>" to  query  a
       table that contains case sensitive patterns. Patterns are case insensi-
       tive by default.

<b>TABLE FORMAT</b>
       The general form of a PCRE table is:

       <b>/</b><i>pattern</i><b>/</b><i>flags result</i>
              When <i>pattern</i> matches the input  string,  use  the  corresponding
              <i>result</i> value.

       <b>!/</b><i>pattern</i><b>/</b><i>flags result</i>
              When  <i>pattern</i>  does  <b>not</b>  match the input string, use the corre-
              sponding <i>result</i> value.

       <b>if /</b><i>pattern</i><b>/</b><i>flags</i>

       <b>endif</b>  If the input string matches /<i>pattern</i>/,  then  match  that  input
              string against the patterns between <b>if</b> and <b>endif</b>.  The <b>if</b>..<b>endif</b>
              can nest.

              Note: do not prepend whitespace to patterns inside <b>if</b>..<b>endif</b>.

              This feature is available in Postfix 2.1 and later.

       <b>if !/</b><i>pattern</i><b>/</b><i>flags</i>

       <b>endif</b>  If the input string does not match /<i>pattern</i>/,  then  match  that
              input  string  against  the  patterns  between <b>if</b> and <b>endif</b>. The
              <b>if</b>..<b>endif</b> can nest.

              Note: do not prepend whitespace to patterns inside <b>if</b>..<b>endif</b>.

              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-whitespace 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 perl-like regular expression. The  expression  delim-
       iter  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:

       <b>i</b> (default: on)
              Toggles the case sensitivity flag. By default, matching is  case
              insensitive.

       <b>m</b> (default: off)
              Toggles the PCRE_MULTILINE flag. When this flag is on, the <b>^</b> and
              <b>$</b> metacharacters match immediately after and immediately  before
              a  newline  character,  respectively, in addition to matching at
              the start and end of the subject string.

       <b>s</b> (default: on)
              Toggles the PCRE_DOTALL flag.  When  this  flag  is  on,  the  <b>.</b>
              metacharacter  matches  the newline character. With Postfix ver-
              sions prior to 2.0, the flag is off by default, which is  incon-
              venient for multi-line message header matching.

       <b>x</b> (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 pat-
              tern, escape it with backslash.

              Note: do not use <b>#</b><i>comment</i> after patterns.

       <b>A</b> (default: off)
              Toggles the PCRE_ANCHORED flag.  When this flag is on, the  pat-
              tern  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.

       <b>E</b> (default: off)
              Toggles the PCRE_DOLLAR_ENDONLY flag. When this flag is on, a  <b>$</b>
              metacharacter in the pattern matches only at the end of the sub-
              ject 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  characters).  This  flag  is
              ignored if PCRE_MULTILINE flag is set.

       <b>U</b> (default: off)
              Toggles  the  ungreedy matching flag.  When this flag is on, the
              pattern matching engine inverts the "greediness" of the  quanti-
              fiers  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.

       <b>X</b> (default: off)
              Toggles  the  PCRE_EXTRA  flag.  When this flag is on, any back-
              slash in a pattern that is followed by a letter that has no spe-
              cial  meaning causes an error, thus reserving these combinations
              for future expansion.

<b>SEARCH ORDER</b>
       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 par-
       ent network search is done, and <i>user@domain</i> mail addresses are not bro-
       ken  up  into  their <i>user</i> and <i>domain</i> constituent parts, nor is <i>user+foo</i>
       broken up into <i>user</i> and <i>foo</i>.

<b>TEXT SUBSTITUTION</b>
       Substitution of substrings (text that  matches  patterns  inside  "()")
       from  the  matched  expression into the result string is requested with
       $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 <b>!</b>) return a result when
       the  expression  does  not  match,  substitutions are not available for
       negated patterns.

<b>EXAMPLE SMTPD ACCESS MAP</b>
       # 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.

<b>EXAMPLE HEADER FILTER MAP</b>
       /^Subject: make money fast/     REJECT
       /^To: friend@public\.com/       REJECT

<b>EXAMPLE BODY FILTER MAP</b>
       # First skip over base 64 encoded text to save CPU cycles.
       # Requires PCRE version 3.
       ~^[[:alnum:]+/]{60,}$~          OK

       # Put your own body patterns here.

<b>SEE ALSO</b>
       <a href="postmap.1.html">postmap(1)</a>, Postfix lookup table manager
       <a href="postconf.5.html">postconf(5)</a>, configuration parameters
       <a href="regexp_table.5.html">regexp_table(5)</a>, format of POSIX regular expression tables

<b>README FILES</b>
       <a href="DATABASE_README.html">DATABASE_README</a>, Postfix lookup table overview

<b>AUTHOR(S)</b>
       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

       Wietse Venema
       Google, Inc.
       111 8th Avenue
       New York, NY 10011, USA

                                                                 PCRE_TABLE(5)
</pre> </body> </html>