postlock Man page

POSTLOCK(1) General Commands Manual 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 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 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.

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)