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POSTLOG(1) General Commands Manual POSTLOG(1)


postlog - Postfix-compatible logging utility


postlog [-iv] [-c config_dir] [-p priority] [-t tag] [text...]


The postlog(1) command implements a Postfix-compatible logging interface for use in, for example, shell scripts.

By default, postlog(1) logs the text given on the command line as one record. If no text is specified on the command line, postlog(1) reads from standard input and logs each input line as one record.

By default, logging is sent to syslogd(8) or postlogd(8); when the standard error stream is connected to a terminal, logging is sent there as well.

The following options are implemented:

Read the configuration file in the named directory instead of the default configuration directory.
Include the process ID in the logging tag. This flag is ignored as of Postfix 3.4, where the PID is always included.
Specifies the logging severity: info, warn, error, fatal, or panic. With Postfix 3.1 and later, the program will pause for 1 second after reporting a fatal or panic condition, just like other Postfix programs.
Specifies the logging tag, that is, the identifying name that appears at the beginning of each logging record. A default tag is used when none is specified.
Enable verbose logging for debugging purposes. Multiple -v options make the software increasingly verbose.


The postlog(1) command is designed to run with set-groupid privileges, so that it can connect to the postlogd(8) daemon process (Postfix 3.7 and later; earlier implementations of this command must not have set-groupid or set-userid permissions).


Directory with the file.


The following parameters are especially relevant to this program.

The text below provides only a parameter summary. See postconf(5) for more details including examples.

The default location of the Postfix and configuration files.
The list of environment variables that a privileged Postfix process will import from a non-Postfix parent process, or name=value environment overrides.
The syslog facility of Postfix logging.
A prefix that is prepended to the process name in syslog records, so that, for example, "smtpd" becomes "prefix/smtpd".

Available in Postfix 3.4 and later:

The name of an optional logfile that is written by the Postfix postlogd(8) service.
The name of the postlogd(8) service entry in


postconf(5), configuration parameters
postlogd(8), Postfix logging
syslogd(8), system logging


The Secure Mailer license must be distributed with this software.


The postlog(1) command was introduced with Postfix version 3.4.


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