1:mod:`syslog` --- Unix syslog library routines 2============================================== 3 4.. module:: syslog 5 :platform: Unix 6 :synopsis: An interface to the Unix syslog library routines. 7 8-------------- 9 10This module provides an interface to the Unix ``syslog`` library routines. 11Refer to the Unix manual pages for a detailed description of the ``syslog`` 12facility. 13 14This module wraps the system ``syslog`` family of routines. A pure Python 15library that can speak to a syslog server is available in the 16:mod:`logging.handlers` module as :class:`SysLogHandler`. 17 18The module defines the following functions: 19 20 21.. function:: syslog(message) 22 syslog(priority, message) 23 24 Send the string *message* to the system logger. A trailing newline is added 25 if necessary. Each message is tagged with a priority composed of a 26 *facility* and a *level*. The optional *priority* argument, which defaults 27 to :const:`LOG_INFO`, determines the message priority. If the facility is 28 not encoded in *priority* using logical-or (``LOG_INFO | LOG_USER``), the 29 value given in the :func:`openlog` call is used. 30 31 If :func:`openlog` has not been called prior to the call to :func:`syslog`, 32 ``openlog()`` will be called with no arguments. 33 34 .. audit-event:: syslog.syslog priority,message syslog.syslog 35 36 37.. function:: openlog([ident[, logoption[, facility]]]) 38 39 Logging options of subsequent :func:`syslog` calls can be set by calling 40 :func:`openlog`. :func:`syslog` will call :func:`openlog` with no arguments 41 if the log is not currently open. 42 43 The optional *ident* keyword argument is a string which is prepended to every 44 message, and defaults to ``sys.argv[0]`` with leading path components 45 stripped. The optional *logoption* keyword argument (default is 0) is a bit 46 field -- see below for possible values to combine. The optional *facility* 47 keyword argument (default is :const:`LOG_USER`) sets the default facility for 48 messages which do not have a facility explicitly encoded. 49 50 .. audit-event:: syslog.openlog ident,logoption,facility syslog.openlog 51 52 .. versionchanged:: 3.2 53 In previous versions, keyword arguments were not allowed, and *ident* was 54 required. The default for *ident* was dependent on the system libraries, 55 and often was ``python`` instead of the name of the Python program file. 56 57 58.. function:: closelog() 59 60 Reset the syslog module values and call the system library ``closelog()``. 61 62 This causes the module to behave as it does when initially imported. For 63 example, :func:`openlog` will be called on the first :func:`syslog` call (if 64 :func:`openlog` hasn't already been called), and *ident* and other 65 :func:`openlog` parameters are reset to defaults. 66 67 .. audit-event:: syslog.closelog "" syslog.closelog 68 69 70.. function:: setlogmask(maskpri) 71 72 Set the priority mask to *maskpri* and return the previous mask value. Calls 73 to :func:`syslog` with a priority level not set in *maskpri* are ignored. 74 The default is to log all priorities. The function ``LOG_MASK(pri)`` 75 calculates the mask for the individual priority *pri*. The function 76 ``LOG_UPTO(pri)`` calculates the mask for all priorities up to and including 77 *pri*. 78 79 .. audit-event:: syslog.setlogmask maskpri syslog.setlogmask 80 81The module defines the following constants: 82 83Priority levels (high to low): 84 :const:`LOG_EMERG`, :const:`LOG_ALERT`, :const:`LOG_CRIT`, :const:`LOG_ERR`, 85 :const:`LOG_WARNING`, :const:`LOG_NOTICE`, :const:`LOG_INFO`, 86 :const:`LOG_DEBUG`. 87 88Facilities: 89 :const:`LOG_KERN`, :const:`LOG_USER`, :const:`LOG_MAIL`, :const:`LOG_DAEMON`, 90 :const:`LOG_AUTH`, :const:`LOG_LPR`, :const:`LOG_NEWS`, :const:`LOG_UUCP`, 91 :const:`LOG_CRON`, :const:`LOG_SYSLOG`, :const:`LOG_LOCAL0` to 92 :const:`LOG_LOCAL7`, and, if defined in ``<syslog.h>``, 93 :const:`LOG_AUTHPRIV`. 94 95Log options: 96 :const:`LOG_PID`, :const:`LOG_CONS`, :const:`LOG_NDELAY`, and, if defined 97 in ``<syslog.h>``, :const:`LOG_ODELAY`, :const:`LOG_NOWAIT`, and 98 :const:`LOG_PERROR`. 99 100 101Examples 102-------- 103 104Simple example 105~~~~~~~~~~~~~~ 106 107A simple set of examples:: 108 109 import syslog 110 111 syslog.syslog('Processing started') 112 if error: 113 syslog.syslog(syslog.LOG_ERR, 'Processing started') 114 115An example of setting some log options, these would include the process ID in 116logged messages, and write the messages to the destination facility used for 117mail logging:: 118 119 syslog.openlog(logoption=syslog.LOG_PID, facility=syslog.LOG_MAIL) 120 syslog.syslog('E-mail processing initiated...') 121