LOG(9) BSD Kernel Manual LOG(9)
log, addlog - log a message from the kernel through the /dev/klog device
#include <sys/syslog.h> void log(int level, const char *format, ...); void addlog(const char *format, ...);
The log() function allows the kernel to send formatted messages to user processes listening on /dev/klog. Usually syslogd(8) monitors /dev/klog for these messages and writes them to a log file. All messages are formatted using printf(9), logged using facility LOG_KERN, and priority level level. The addlog() function is used to build a log message in steps, by adding information to an initial call to log().
syslog(3), syslogd(8), printf(9) MirBSD #10-current May 12, 1997 1