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POSTLOCK(1)                 General Commands Manual                POSTLOCK(1)

<b>NAME</b>
       postlock - lock mail folder and execute command

<b>SYNOPSIS</b>
       <b>postlock</b> [<b>-c</b> <i>config</i><b>_</b><i>dir</i>] [<b>-l</b> <i>lock</i><b>_</b><i>style</i>]
               [<b>-v</b>] <i>file command...</i>

<b>DESCRIPTION</b>
       The  <a href="postlock.1.html"><b>postlock</b>(1)</a>  command locks <i>file</i> for exclusive access, and executes
       <i>command</i>. The locking method is compatible with the  Postfix  UNIX-style
       local delivery agent.

       Options:

       <b>-c</b> <i>config</i><b>_</b><i>dir</i>
              Read  the  <a href="postconf.5.html"><b>main.cf</b></a>  configuration  file  in  the named directory
              instead of the default configuration directory.

       <b>-l</b> <i>lock</i><b>_</b><i>style</i>
              Override the locking method  specified  via  the  <b><a href="postconf.5.html#mailbox_delivery_lock">mailbox_deliv</a>-</b>
              <b><a href="postconf.5.html#mailbox_delivery_lock">ery_lock</a></b> configuration parameter (see below).

       <b>-v</b>     Enable  verbose  logging  for  debugging  purposes.  Multiple <b>-v</b>
              options make the software increasingly verbose.

       Arguments:

       <i>file</i>   A mailbox file. The user should have read/write permission.

       <i>command...</i>
              The command to  execute  while  <i>file</i>  is  locked  for  exclusive
              access.   The  command is executed directly, i.e. without inter-
              pretation by a shell command interpreter.

<b>DIAGNOSTICS</b>
       The result status is 75 (EX_TEMPFAIL) when <a href="postlock.1.html"><b>postlock</b>(1)</a> could  not  per-
       form  the  requested operation.  Otherwise, the exit status is the exit
       status from the command.

<b>BUGS</b>
       With remote file systems, the ability to acquire a lock does not neces-
       sarily  eliminate access conflicts. Avoid file access by processes run-
       ning on different machines.

<b>ENVIRONMENT</b>
       <b>MAIL_CONFIG</b>
              Directory with Postfix configuration files.

       <b>MAIL_VERBOSE</b>
              Enable verbose logging for debugging purposes.

<b>CONFIGURATION PARAMETERS</b>
       The following <a href="postconf.5.html"><b>main.cf</b></a> parameters are especially relevant to  this  pro-
       gram.   The  text  below  provides  only a parameter summary. See <a href="postconf.5.html"><b>post-</b></a>
       <a href="postconf.5.html"><b>conf</b>(5)</a> for more details including examples.

<b>LOCKING CONTROLS</b>
       <b><a href="postconf.5.html#deliver_lock_attempts">deliver_lock_attempts</a> (20)</b>
              The maximal number of attempts to acquire an exclusive lock on a
              mailbox file or <a href="bounce.8.html"><b>bounce</b>(8)</a> logfile.

       <b><a href="postconf.5.html#deliver_lock_delay">deliver_lock_delay</a> (1s)</b>
              The  time  between  attempts  to  acquire an exclusive lock on a
              mailbox file or <a href="bounce.8.html"><b>bounce</b>(8)</a> logfile.

       <b><a href="postconf.5.html#stale_lock_time">stale_lock_time</a> (500s)</b>
              The time after which  a  stale  exclusive  mailbox  lockfile  is
              removed.

       <b><a href="postconf.5.html#mailbox_delivery_lock">mailbox_delivery_lock</a> (see 'postconf -d' output)</b>
              How  to  lock  a  UNIX-style  <a href="local.8.html"><b>local</b>(8)</a> mailbox before attempting
              delivery.

<b>RESOURCE AND RATE CONTROLS</b>
       <b><a href="postconf.5.html#fork_attempts">fork_attempts</a> (5)</b>
              The maximal number of attempts to fork() a child process.

       <b><a href="postconf.5.html#fork_delay">fork_delay</a> (1s)</b>
              The delay between attempts to fork() a child process.

<b>MISCELLANEOUS CONTROLS</b>
       <b><a href="postconf.5.html#config_directory">config_directory</a> (see 'postconf -d' output)</b>
              The default location of the Postfix <a href="postconf.5.html">main.cf</a> and  <a href="master.5.html">master.cf</a>  con-
              figuration files.

<b>SEE ALSO</b>
       <a href="postconf.5.html">postconf(5)</a>, configuration parameters

<b>LICENSE</b>
       The Secure Mailer license must be distributed with this software.

<b>AUTHOR(S)</b>
       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

                                                                   POSTLOCK(1)
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