    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 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 mail-
                  box_delivery_lock  configuration   parameter   (see
                  below).

           -v     Enable verbose logging for debugging purposes. Mul-
                  tiple -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 interpretation  by  a  shell
                  command interpreter.

    DIAGNOSTICS
           The  result status is 75 (EX_TEMPFAIL) when postlock could
           not perform 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 necessarily  eliminate  access  conflicts.  Avoid
           file access by processes running 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 program.  The text below provides only a parameter
           summary.  See postconf(5) for more details including exam-
           ples.

    LOCKING CONTROLS
           deliver_lock_attempts (20)
                  The maximal number of attempts to acquire an exclu-
                  sive 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 pro-
                  cess.

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

    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

                                                          POSTLOCK(1)