kutil_openlog
—
configure log message sink
The
kutil_openlog
()
function configures output for the
kutil_log(3)
family of functions. By default, these functions log to
stderr
and inherit the initial output buffering
behaviour (see
setvbuf(3)).
If file is not
NULL
,
kutil_openlog
()
first redirects stderr to file.
Then, regardless of whether file is
NULL
, the output buffering of the stream is set to
line buffered.
CGI scripts invoking long-running child processes via
fork(2)
should use this function with a valid file as the web
server might wait for all file descriptors to close before closing the
request connection.
The kutil_openlog
() function returns zero
on failure (system error) and non-zero on success. If
kutil_openlog
() fails to re-open
stderr, the output stream may no longer be operable:
the caller should exit.
The kutil_openlog
() function was written
by Kristaps Dzonsons
<kristaps@bsd.lv>.
In most situations, file is configured in
the default log directory, which is not writable to the CGI process. Thus,
file must be pre-created and be writable to the CGI
process. Otherwise, kutil_openlog
() will fail to
create the file and exit with failure.