linux c syslog LOG_CONS off
linux c syslog 控制台不输出
openlog("SEC", LOG_PID, LOG_USER);
The option argument to openlog() is an OR of any of these:
Write directly to system console if there is an error while sending to system logger.
Open the connection immediately (normally, the connection is opened when the first message is logged).
Don't wait for child processes that may have been created while logging the message. (The GNU C library does not create a child process, so this option has no effect on Linux.)
The converse of LOG_NDELAY; opening of the connection is delayed until syslog() is called. (This is the default, and need not be specified.)
(Not in POSIX.1-2001 or POSIX.1-2008.) Print to stderr as well.
Include PID with each message.
linux c openlog example
Here is an example of openlog, syslog, and closelog:
This example sets the logmask so that debug and informational messages get discarded without ever reaching Syslog. So the second syslog in the example does nothing.
#include <syslog.h> setlogmask (LOG_UPTO (LOG_NOTICE)); openlog ("exampleprog", LOG_CONS | LOG_PID | LOG_NDELAY, LOG_LOCAL1); syslog (LOG_NOTICE, "Program started by User %d", getuid ()); syslog (LOG_INFO, "A tree falls in a forest"); closelog ();