POSTLOCK(1)                                           POSTLOCK(1)

NAME
       postlock - lock mail folder and execute command

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

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. See the Postfix main.cf file for syntax
       details and for default values.

Locking controls
       deliver_lock_attempts
              Limit the number of attempts to acquire  an  exclu-
              sive lock.

       deliver_lock_delay
              Time  in  seconds  between  successive  attempts to
              acquire an exclusive lock.

       stale_lock_time
              Limit the time after which a stale lock is removed.

       mailbox_delivery_lock
              What  file locking method(s) to use when delivering
              to a UNIX-style mailbox.  The  default  setting  is
              system  dependent.   For  a  list of available file
              locking methods, use the postconf -l command.

Resource controls
       fork_attempts
              Number of attempts to fork() a process before  giv-
              ing up.

       fork_delay
              Delay   in   seconds   between   successive  fork()
              attempts.

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

                                                                1