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
postconf(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
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
Wietse Venema
Google, Inc.
111 8th Avenue
New York, NY 10011, USA