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Neither the name of the University nor the names of its contributors .\" may be used to endorse or promote products derived from this software .\" without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .\" @(#)syslog.3 8.1 (Berkeley) 6/4/93 .\" .TH SYSLOG 3 "28 January 1997" GNO "Library Routines" .SH NAME .BR syslog , .BR vsyslog , .BR openlog , .BR closelog , .BR setlogmask \- control system log .SH SYNOPSIS #include .br #include .sp 1 void \fBsyslog\fR (int \fIpriority\fR, const char *\fImessage\fR, ...); .br void \fBvsyslog\fR (int \fIpriority\fR, const char *\fImessage\fR, va_list \fBargs\fR); .br void \fBopenlog\fR (const char *\fIident\fR, int \fIlogopt\fR, int \fIfacility\fR); .br void \fBcloselog\fR (void); .br int \fBsetlogmask\fR (int \fImaskpri\fR); .SH DESCRIPTION The .BR syslog function writes .I message to the system message logger. The message is then written to the system console, log files, logged-in users, or forwarded to other machines as appropriate. (See .BR syslogd (8).) .LP The message is identical to a .BR printf (3) format string, except that .BR %m is replaced by the current error message. (As denoted by the global variable .IR errno ; see .BR strerror (3).) A trailing newline is added if none is present. .LP The .BR vsyslog function is an alternate form in which the arguments have already been captured using the variable-length argument facilities of .BR varargs (3). .LP The message is tagged with .IR priority . Priorities are encoded as a .I facility and a .IR level . The facility describes the part of the system generating the message. The level is selected from the following .IR ordered (high to low) list: .RS .IP "\fBLOG_EMERG\fR" A panic condition. This is normally broadcast to all users. .IP "\fBLOG_ALERT\fR" A condition that should be corrected immediately, such as a corrupted system database. .IP "\fBLOG_CRIT\fR" Critical conditions, e.g., hard device errors. .IP "\fBLOG_ERR\fR" Errors. .IP "\fBLOG_WARNING\fR" Warning messages. .IP "\fBLOG_NOTICE\fR" Conditions that are not error conditions, but should possibly be handled specially. .IP "\fBLOG_INFO\fR" Informational messages. .IP "\fBLOG_DEBUG\fR" Messages that contain information normally of use only when debugging a program. .RE .LP The .BR openlog function provides for more specialized processing of the messages sent by .BR syslog and .BR vsyslog . The parameter .I ident is a string that will be prepended to every message. The .I logopt argument is a bit field specifying logging options, which is formed by .BR OR 'ing one or more of the following values: .RS .IP "\fBLOG_CONS\fR" If .BR syslog cannot pass the message to .BR syslogd (8) it will attempt to write the message to the console .BR .ttyco . .IP "\fBLOG_NDELAY\fR" Open the connection to .BR syslogd (8) immediately. Normally the open is delayed until the first message is logged. Useful for programs that need to manage the order in which file descriptors are allocated. .IP "\fBLOG_PERROR\fR" Write the message to standard error output as well to the system log. .IP "\fBLOG_PID\fR" Log the process id with each message: useful for identifying instantiations of daemons. .RE .LP The .I facility parameter encodes a default facility to be assigned to all messages that do not have an explicit facility encoded: .RS .IP "\fBLOG_AUTH\fR" The authorization system: .BR login (1), .BR su (1), .BR getty (8), etc. .IP "\fBLOG_AUTHPRIV\fR" The same as .BR LOG_AUTH , but logged to a file readable only by selected individuals. .IP "\fBLOG_CRON\fR" The cron daemon: .BR cron (8). .IP "\fBLOG_DAEMON\fR" System daemons, such as .BR routed (8), that are not provided for explicitly by other facilities. .IP "\fBLOG_FTP\fR" The file transfer protocol daemon: .BR ftpd (8). .IP "\fBLOG_KERN\fR" Messages generated by the kernel. These cannot be generated by any user processes. .IP "\fBLOG_LPR\fR" The line printer spooling system: .BR lpr (1), .BR lpc (8), .BR lpd (8), etc. .IP "\fBLOG_MAIL\fR" The mail system. .IP "\fBLOG_NEWS\fR" The network news system. .IP "\fBLOG_SYSLOG\fR" Messages generated internally by .BR syslogd (8). .IP "\fBLOG_USER\fR" Messages generated by random user processes. This is the default facility identifier if none is specified. .IP "\fBLOG_UUCP\fR" The uucp system. .IP "\fBLOG_LOCAL0\fR" Reserved for local use. Similarly for .BR LOG_LOCAL1 through .BR LOG_LOCAL7 . .RE .LP The .BR closelog function can be used to close the log file. .LP The .BR setlogmask function sets the log priority mask to .I maskpri and returns the previous mask. Calls to .BR syslog with a priority not set in .I maskpri are rejected. The mask for an individual priority .I pri is calculated by the macro .BR LOG_MASK pri ; the mask for all priorities up to and including .I toppri is given by the macro .BR LOG_UPTO toppri ; . The default allows all priorities to be logged. .SH RETURN VALUES The routines .BR closelog , .BR openlog , .BR syslog and .BR vsyslog return no value. .LP The routine .BR setlogmask always returns the previous log mask level. .SH EXAMPLES .nf syslog(LOG_ALERT, "who: internal error 23"); openlog("ftpd", LOG_PID | LOG_NDELAY, LOG_FTP); setlogmask(LOG_UPTO(LOG_ERR)); syslog(LOG_INFO, "Connection from host %d", CallingHost); syslog(LOG_INFO|LOG_LOCAL2, "foobar error: %m"); .fi .SH SEE ALSO .BR logger (1), .BR syslogd (8) .SH HISTORY These functions appeared in 4.2BSD.