syslog — Unix syslog library routines

Python documentation

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This module provides an interface to the Unix syslog library routines. Refer to the Unix manual pages for a detailed description of the syslog facility.

This module wraps the system syslog family of routines. A pure Python library that can speak to a syslog server is available in the

logging.handlers

module as

SysLogHandler

.

The module defines the following functions:

syslog.syslog(message)

syslog.syslog(priority, message)Send the string message to the system logger. A trailing newline is added if necessary. Each message is tagged with a priority composed of a facility and a level. The optional priority argument, which defaults to

LOG_INFO

, determines the message priority. If the facility is not encoded in priority using logical-or (LOG_INFO|LOG_USER), the value given in the

openlog()

call is used.

If

openlog()

has not been called prior to the call to syslog(), openlog() will be called with no arguments.

Raises an

auditing event

syslog.syslog with arguments priority, message.

Changed in version 3.2: In previous versions,

openlog()

would not be called automatically if it wasn’t called prior to the call to syslog(), deferring to the syslog implementation to call openlog().

Changed in version 3.12: This function is restricted in subinterpreters. (Only code that runs in multiple interpreters is affected and the restriction is not relevant for most users.)

openlog()

must be called in the main interpreter before syslog() may be used in a subinterpreter. Otherwise it will raise

RuntimeError

.

syslog.openlog([ident[, logoption[, facility]]])

Logging options of subsequent

syslog()

calls can be set by calling openlog(). syslog() will call openlog() with no arguments if the log is not currently open.

The optional ident keyword argument is a string which is prepended to every message, and defaults to sys.argv[0] with leading path components stripped. The optional logoption keyword argument (default is 0) is a bit field – see below for possible values to combine. The optional facility keyword argument (default is

LOG_USER

) sets the default facility for messages which do not have a facility explicitly encoded.

Raises an

auditing event

syslog.openlog with arguments ident, logoption, facility.

Changed in version 3.2: In previous versions, keyword arguments were not allowed, and ident was required.

Changed in version 3.12: This function is restricted in subinterpreters. (Only code that runs in multiple interpreters is affected and the restriction is not relevant for most users.) This may only be called in the main interpreter. It will raise

RuntimeError

if called in a subinterpreter.

syslog.closelog()

Reset the syslog module values and call the system library closelog().

This causes the module to behave as it does when initially imported. For example,

openlog()

will be called on the first

syslog()

call (if openlog() hasn’t already been called), and ident and other openlog() parameters are reset to defaults.

Raises an

auditing event

syslog.closelog with no arguments.

Changed in version 3.12: This function is restricted in subinterpreters. (Only code that runs in multiple interpreters is affected and the restriction is not relevant for most users.) This may only be called in the main interpreter. It will raise

RuntimeError

if called in a subinterpreter.

syslog.setlogmask(maskpri)

Set the priority mask to maskpri and return the previous mask value. Calls to

syslog()

with a priority level not set in maskpri are ignored. The default is to log all priorities. The function LOG_MASK(pri) calculates the mask for the individual priority pri. The function LOG_UPTO(pri) calculates the mask for all priorities up to and including pri.

Raises an

auditing event

syslog.setlogmask with argument maskpri.

The module defines the following constants:

syslog.LOG_EMERG

syslog.LOG_ALERT

syslog.LOG_CRIT

syslog.LOG_ERR

syslog.LOG_WARNING

syslog.LOG_NOTICE

syslog.LOG_INFO

syslog.LOG_DEBUG

Priority levels (high to low).

syslog.LOG_AUTH

syslog.LOG_AUTHPRIV

syslog.LOG_CRON

syslog.LOG_DAEMON

syslog.LOG_FTP

syslog.LOG_INSTALL

syslog.LOG_KERN

syslog.LOG_LAUNCHD

syslog.LOG_LPR

syslog.LOG_MAIL

syslog.LOG_NETINFO

syslog.LOG_NEWS

syslog.LOG_RAS

syslog.LOG_REMOTEAUTH

syslog.LOG_SYSLOG

syslog.LOG_USER

syslog.LOG_UUCP

syslog.LOG_LOCAL0

syslog.LOG_LOCAL1

syslog.LOG_LOCAL2

syslog.LOG_LOCAL3

syslog.LOG_LOCAL4

syslog.LOG_LOCAL5

syslog.LOG_LOCAL6

syslog.LOG_LOCAL7

Facilities, depending on availability in <syslog.h> for

LOG_AUTHPRIV

,

LOG_FTP

,

LOG_NETINFO

,

LOG_REMOTEAUTH

,

LOG_INSTALL

and

LOG_RAS

.

Changed in version 3.13: Added

LOG_FTP

,

LOG_NETINFO

,

LOG_REMOTEAUTH

,

LOG_INSTALL

,

LOG_RAS

, and

LOG_LAUNCHD

.

syslog.LOG_PID

syslog.LOG_CONS

syslog.LOG_NDELAY

syslog.LOG_ODELAY

syslog.LOG_NOWAIT

syslog.LOG_PERROR

Log options, depending on availability in <syslog.h> for

LOG_ODELAY

,

LOG_NOWAIT

and

LOG_PERROR

.

Examples

Simple example

A simple set of examples:

importsyslogsyslog.syslog('Processing started')iferror:syslog.syslog(syslog.LOG_ERR,'Processing started')An example of setting some log options, these would include the process ID in logged messages, and write the messages to the destination facility used for mail logging:

syslog.openlog(logoption=syslog.LOG_PID,facility=syslog.LOG_MAIL)syslog.syslog('E-mail processing initiated...')