1SD-DAEMON(3) sd-daemon SD-DAEMON(3)
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6 sd-daemon, SD_EMERG, SD_ALERT, SD_CRIT, SD_ERR, SD_WARNING, SD_NOTICE,
7 SD_INFO, SD_DEBUG - APIs for new-style daemons
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10 #include <systemd/sd-daemon.h>
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12 pkg-config --cflags --libs libsystemd
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15 sd-daemon.h provides APIs for new-style daemons, as implemented by the
16 systemd(1) service manager.
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18 See sd_listen_fds(3), sd_notify(3), sd_booted(3), sd_is_fifo(3),
19 sd_watchdog_enabled(3) for more information about the functions
20 implemented. In addition to these functions, a couple of logging
21 prefixes are defined as macros:
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23 #define SD_EMERG "<0>" /* system is unusable */
24 #define SD_ALERT "<1>" /* action must be taken immediately */
25 #define SD_CRIT "<2>" /* critical conditions */
26 #define SD_ERR "<3>" /* error conditions */
27 #define SD_WARNING "<4>" /* warning conditions */
28 #define SD_NOTICE "<5>" /* normal but significant condition */
29 #define SD_INFO "<6>" /* informational */
30 #define SD_DEBUG "<7>" /* debug-level messages */
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32 These prefixes are intended to be used in conjunction with stderr-based
33 logging (or stdout-based logging) as implemented by systemd. If a
34 systemd service definition file is configured with
35 StandardError=journal or StandardError=kmsg (and similar with
36 StandardOutput=), these prefixes can be used to encode a log level in
37 lines printed. This is similar to the kernel printk()-style logging.
38 See klogctl(2) for more information.
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40 The log levels are identical to syslog(3)'s log level system. To use
41 these prefixes simply prefix every line with one of these strings. A
42 line that is not prefixed will be logged at the default log level
43 SD_INFO.
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45 Example 1. Hello World
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47 A daemon may log with the log level NOTICE by issuing this call:
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49 fprintf(stderr, SD_NOTICE "Hello World!\n");
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52 These APIs are implemented as a shared library, which can be compiled
53 and linked to with the libsystemd pkg-config(1) file.
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56 systemd(1), sd_listen_fds(3), sd_notify(3), sd_booted(3),
57 sd_is_fifo(3), sd_watchdog_enabled(3), daemon(7), systemd.service(5),
58 systemd.socket(5), fprintf(3), pkg-config(1)
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62systemd 253 SD-DAEMON(3)