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_delivery_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
interpretation by a shell command interpreter.
DIAGNOSTICS
The result status is 75 (EX_TEMPFAIL) when
postlock(1)
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 (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 (8)
logfile.
- deliver_lock_delay (1s)
- The time between attempts to acquire an exclusive lock on a
mailbox file or (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 (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
configuration files.
SEE ALSO
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