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.