|SENDSYSLOG(2)||System Calls Manual||SENDSYSLOG(2)|
sendsyslog — send
a message to syslogd
char *msg, size_t
sendsyslog() function is used to
transmit a syslog(3) formatted message
direct to syslogd(8) without requiring
the allocation of a socket. The msg is not NUL
terminated and its len is limited to 8192 bytes. If
LOG_CONS is specified in the
flags argument, and
syslogd(8) is not accepting messages,
the message will be sent to the console. This is used internally by
syslog_r(3), so that messages can be
sent during difficult situations. If sending to
syslogd(8) fails, dropped messages are
counted. When syslogd(8) works again, a
warning with the counter and error number is logged.
To receive messages from the kernel,
syslogd(8) has to create a datagram
socket pair and register one end. This registration is done by opening the
/dev/klog device and passing one file descriptor of
the socket pair as argument to ioctl(2)
LIOCSFD invoked on the klog file descriptor. After
that the messages can be be read from the other end of the socket pair. By
utilizing /dev/klog the access to log messages is
limited to processes that may open this device.
Upon successful completion, the value 0 is returned; otherwise the value -1 is returned and the global variable errno is set to indicate the error.
sendsyslog() can fail if:
sendsyslog() function call appeared in
OpenBSD 5.6. The flags
argument was added in OpenBSD 6.0.
|September 27, 2017||OpenBSD-current|