POSTLOCK(1)                                                        POSTLOCK(1)

NAME
       postlock - lock mail folder and execute command

SYNOPSIS
       postlock [-c config_dir] [-l lock_style]
               [-v] file command...

DESCRIPTION
       The  postlock(1)  command locks file for exclusive access, and executes
       command. The locking method is compatible with the  Postfix  UNIX-style
       local delivery agent.

       Options:

       -c config_dir
              Read  the  main.cf  configuration  file  in  the named directory
              instead of the default configuration directory.

       -l lock_style
              Override the locking method  specified  via  the  mailbox_deliv-
              ery_lock configuration parameter (see below).

       -v     Enable  verbose  logging  for  debugging  purposes.  Multiple -v
              options make the software increasingly verbose.

       Arguments:

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

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

DIAGNOSTICS
       The result status is 75 (EX_TEMPFAIL) when postlock(1) could  not  per-
       form  the  requested operation.  Otherwise, the exit status is the exit
       status from the command.

BUGS
       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.

ENVIRONMENT
       MAIL_CONFIG
              Directory with Postfix configuration files.

       MAIL_VERBOSE
              Enable verbose logging for debugging purposes.

CONFIGURATION PARAMETERS
       The following main.cf parameters are especially relevant to  this  pro-
       gram.   The  text  below  provides  only a parameter summary. See post-
       conf(5) for more details including examples.

LOCKING CONTROLS
       deliver_lock_attempts (20)
              The maximal number of attempts to acquire an exclusive lock on a
              mailbox file or bounce(8) logfile.

       deliver_lock_delay (1s)
              The  time  between  attempts  to  acquire an exclusive lock on a
              mailbox file or bounce(8) logfile.

       stale_lock_time (500s)
              The time after which  a  stale  exclusive  mailbox  lockfile  is
              removed.

       mailbox_delivery_lock (see 'postconf -d' output)
              How  to  lock  a  UNIX-style  local(8) mailbox before attempting
              delivery.

RESOURCE AND RATE CONTROLS
       fork_attempts (5)
              The maximal number of attempts to fork() a child process.

       fork_delay (1s)
              The delay between attempts to fork() a child process.

MISCELLANEOUS CONTROLS
       config_directory (see 'postconf -d' output)
              The default location of the Postfix main.cf and  master.cf  con-
              figuration files.

       import_environment (see 'postconf -d' output)
              The  list  of  environment  variables  that a privileged Postfix
              process will  import  from  a  non-Postfix  parent  process,  or
              name=value environment overrides.

SEE ALSO
       postconf(5), configuration parameters

LICENSE
       The Secure Mailer license must be distributed with this software.

AUTHOR(S)
       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)