syslog()

Arguments:

priority

The priority of the message; see Message levels, below.

message

The message that you want to write. This message is identical to a printf()-format string, except that %m is replaced by the current error message (as denoted by the global variable errno). A trailing newline is added if none is present.

The formatting characters that you use in the message determine any additional arguments.

Library:

libc

Use the -l c option to qcc to link against this library. This library is usually included automatically.

Description:

The syslog() function writes message to the system message logger. (See the slogger2 command.)

The vsyslog() function is an alternate form in which the arguments have already been captured using the variable-length argument facilities of <stdarg.h>.

Message levels

The message is tagged with priority. Priorities are encoded as a facility and a level. The facility describes the part of the system generating the message:

LOG_KERN

Kernel messages.

LOG_USER

Random user-level messages.

LOG_MAIL

Mail system.

LOG_DAEMON

System daemons.

LOG_AUTH

Security/authorization messages.

LOG_LPR

Line printer subsystem.

LOG_NEWS

Network news subsystem.

LOG_UUCP

UUCP subsystem.

LOG_CRON

Clock daemon.

LOG_AUTHPRIV

Security/authorization messages (private).

LOG_FTP

ftp daemon.

LOG_LOCAL0 through LOG_LOCAL7

Reserved for local use.

The level is selected from the following list (ordered from high to low):

LOG_EMERG

A panic condition. This is normally broadcast to all users.

LOG_ALERT

A condition that should be corrected immediately, such as a corrupted system database.

LOG_CRIT

Critical conditions (for example, hard device errors).

LOG_ERR

General errors.

LOG_WARNING

Warning messages.

LOG_NOTICE

Conditions that aren't error conditions, but should possibly be specially handled.

LOG_INFO

Informational messages.

LOG_DEBUG

Messages that contain information normally of use only when debugging a program.

Examples:

syslog(LOG_ALERT, "who: internal error 23");

openlog("Nfs", LOG_PID|LOG_PERROR, LOG_DAEMON);
setlogmask(LOG_UPTO(LOG_ERR));
syslog(LOG_INFO, "Opening file: %s", filename);

syslog(LOG_INFO|LOG_LOCAL2, "foobar error: %m");

Classification:

POSIX 1003.1