- See also
- - detach_IO/1 to detach normal
I/O of the process and remove it from the process group.
- fork/1 to create a daemon process.
- library(uid) to manage user identifiers (e.g., drop root
privileges).
This library provides an interface to the Unix syslog()
facility. The interface is an almost direct translation of the POSIX
syslog API, with two additions:
- syslog/3 exploits format/3
to format syslog messages
- The library integrates into
library(debug) using
prolog:debug_print_hook/3,
where debug topics are mapped to syslog priorities and
remaining debug topics are mapped to the syslog priority debug.
Note that this interface makes no attempt to abstract over logging
facilities of operating systems. We expect that such abstractions will
be implemented at the Prolog level using multiple integrations into
library(debug).
- [det]openlog(+Ident:atom,
+Options:list(atom), +Facility:atom)
- Open system log. This predicate provides a direct interface into the
openlog()
library call. If the library call is successful, it runs at_halt(closelog)
to ensure closing the system log on clean exit.
| Ident | prepended to every message, and is
typically set to the program name. |
| Options | is a list of options. Values are
corresponding C options, after removing =LOG_= and translation to lower
case: cons, ndelay, nowait, odelay,
perror, pid. |
| Facility | is one of auth, authpriv, cron, daemon,
ftp, kern, local0 ... local7, lpr, mail,
news, syslog, user or uucp. |
- [det]syslog(+Priority,
+Message)
- Send a message to the system log. Note that syslog/2
implicitly opens a connection to the system log if such a connection has
not been opened explicitly using openlog/3.
| Priority | is one of emerg, alert, crit, err,
warning, notice, info or debug. |
- [det]syslog(+Priority,
+Format, +Args)
- Send a formatted message to the system log if system logging is opened
using openlog/3. This predicate
combined format/3 with
syslog/2. If there is no open
syslog connection, syslog/3 calls
print_message/2.
- [det]closelog
- Close the system log.
- [semidet,multifile]prolog:debug_print_hook(+Topic,
+Format, +Args)
- Integration of debug/3 with the syslog
facility. If syslog is enabled, debug/3 is
re-routed to use the syslog facilities. If the topic of the debug
message matches one of the sylog
priority values (see syslog/2),
the message is sent with the corresponding syslog priority. Otherwise it
it sent with the
debug priority.
