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<html> <head> </head> <body> <pre>



PCRE_TABLE(5)                                       PCRE_TABLE(5)


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

<b>SYNOPSIS</b>
       pcre:/etc/postfix/filename

<b>DESCRIPTION</b>
       The  Postfix  mail system uses optional tables for address
       rewriting or mail routing. These tables are usually in <b>dbm</b>
       or  <b>db</b>  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 <b>postconf</b> <b>-m</b> command.

       The general form of a PCRE table is:

       blanks and comments
              Blank  lines  are  ignored,  as are lines beginning
              with `#'.

       leading whitespace
              Lines that begin with whitespace continue the  pre-
              vious line.

       <i>pattern</i> <i>result</i>
              When  <i>pattern</i> matches a search string, use the cor-
              responding <i>result</i>. A line that  starts  with  white
              space continues the preceding line.

       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, although follow-
       ing the second slash with an `i' flag will  reverse  this.
       Other  flags  are supported, but the only other useful one
       is `U', which makes matching ungreedy (see PCRE documenta-
       tion and source for more info).

       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  <i>user@domain</i> mail addresses are not
       broken 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>.

       Patterns  are  applied  in  the  order as specified in the
       table, until a pattern is found that  matches  the  search
       string.




                                                                1





PCRE_TABLE(5)                                       PCRE_TABLE(5)


       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.

<b>EXAMPLES</b>
       # Protect your outgoing majordomo exploders
       /^(?!owner-)(.*)-outgoing@(my.domain)$/    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@connect.com.au$/
        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>SEE</b> <b>ALSO</b>
       <a href="regexp_table.5.html">regexp_table(5)</a> format of POSIX regular expression tables

<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





















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