sd-daemon
systemd
Developer
Lennart
Poettering
lennart@poettering.net
sd-daemon
3
sd-daemon
SD_EMERG
SD_ALERT
SD_CRIT
SD_ERR
SD_WARNING
SD_NOTICE
SD_INFO
SD_DEBUG
APIs for
new-style daemons
#include <systemd/sd-daemon.h>
pkg-config --cflags --libs libsystemd
Description
sd-daemon.h provide APIs for new-style
daemons, as implemented by the
systemd1
init system.
See
sd_listen_fds3,
sd_notify3,
sd_booted3,
sd_is_fifo3,
sd_watchdog_enabled3
for more information about the functions implemented. In addition
to these functions, a couple of logging prefixes are defined as
macros:
#define SD_EMERG "<0>" /* system is unusable */
#define SD_ALERT "<1>" /* action must be taken immediately */
#define SD_CRIT "<2>" /* critical conditions */
#define SD_ERR "<3>" /* error conditions */
#define SD_WARNING "<4>" /* warning conditions */
#define SD_NOTICE "<5>" /* normal but significant condition */
#define SD_INFO "<6>" /* informational */
#define SD_DEBUG "<7>" /* debug-level messages */
These prefixes are intended to be used in conjunction with
stderr-based logging as implemented by systemd. If a systemd
service definition file is configured with
StandardError=journal,
StandardError=syslog or
StandardError=kmsg, these prefixes can be used
to encode a log level in lines printed. This is similar to the
kernel printk()-style logging. See
klogctl2
for more information.
The log levels are identical to
syslog3's
log level system. To use these prefixes simply prefix every line
with one of these strings. A line that is not prefixed will be
logged at the default log level SD_INFO.
Hello World
A daemon may log with the log level NOTICE by issuing this
call:
fprintf(stderr, SD_NOTICE "Hello World!\n");
See Also
systemd1,
sd_listen_fds3,
sd_notify3,
sd_booted3,
sd_is_fifo3,
sd_watchdog_enabled3,
daemon7,
systemd.service5,
systemd.socket5,
fprintf3,
pkg-config1