-/* Informs systemd about changed daemon state. This takes a numeber of
- * newline seperated environment-style variable assignments in a
- * string. The following strings are known:
- *
- * READY=1 Tells systemd that daemon startup is finished (only
- * relevant for services of Type=notify). The passed
- * argument is a boolean "1" or "0". Since there is
- * little value in signalling non-readiness the only
- * value daemons should send is "READY=1".
- *
- * STATUS=... Passes a status string back to systemd that
- * describes the daemon state. This is free-from and
- * can be used for various purposes: general state
- * feedback, fsck-like programs could pass completion
- * percentages and failing programs could pass a human
- * readable error message. Example: "STATUS=Completed
- * 66% of file system check..."
- *
- * ERRNO=... If a daemon fails, the errno-style error code,
- * formatted as string. Example: "ERRNO=2" for ENOENT.
- *
- * BUSERROR=... If a daemon fails, the D-Bus error-style error
- * code. Example: "BUSERROR=org.freedesktop.DBus.Error.TimedOut"
- *
- * MAINPID=... The main pid of a daemon, in case systemd did not
- * fork off the process itself. Example: "MAINPID=4711"
- *
- * See sd_notifyf() for more complete examples.
- */
+/*
+ Helper call for identifying a passed file descriptor. Returns 1 if
+ the file descriptor is a POSIX Message Queue of the specified name,
+ 0 otherwise. If path is NULL a message queue name check is not
+ done. Returns a negative errno style error code on failure.
+*/
+int sd_is_mq(int fd, const char *path);
+
+/*
+ Informs systemd about changed daemon state. This takes a number of
+ newline separated environment-style variable assignments in a
+ string. The following variables are known:
+
+ READY=1 Tells systemd that daemon startup is finished (only
+ relevant for services of Type=notify). The passed
+ argument is a boolean "1" or "0". Since there is
+ little value in signaling non-readiness the only
+ value daemons should send is "READY=1".
+
+ STATUS=... Passes a single-line status string back to systemd
+ that describes the daemon state. This is free-from
+ and can be used for various purposes: general state
+ feedback, fsck-like programs could pass completion
+ percentages and failing programs could pass a human
+ readable error message. Example: "STATUS=Completed
+ 66% of file system check..."
+
+ ERRNO=... If a daemon fails, the errno-style error code,
+ formatted as string. Example: "ERRNO=2" for ENOENT.
+
+ BUSERROR=... If a daemon fails, the D-Bus error-style error
+ code. Example: "BUSERROR=org.freedesktop.DBus.Error.TimedOut"
+
+ MAINPID=... The main pid of a daemon, in case systemd did not
+ fork off the process itself. Example: "MAINPID=4711"
+
+ Daemons can choose to send additional variables. However, it is
+ recommended to prefix variable names not listed above with X_.
+
+ Returns a negative errno-style error code on failure. Returns > 0
+ if systemd could be notified, 0 if it couldn't possibly because
+ systemd is not running.
+
+ Example: When a daemon finished starting up, it could issue this
+ call to notify systemd about it:
+
+ sd_notify(0, "READY=1");
+
+ See sd_notifyf() for more complete examples.
+
+ See sd_notify(3) for more information.
+*/