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
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