SD_JOURNAL_STREAM_FD(3) 				       sd_journal_stream_fd					   SD_JOURNAL_STREAM_FD(3)

NAME

       sd_journal_stream_fd - Create log stream file descriptor to the journal

SYNOPSIS

       #include <systemd/sd-journal.h>

       int sd_journal_stream_fd(const char* identifier, int priority, int level_prefix);

DESCRIPTION

       sd_journal_stream_fd() may be used to create a log stream file descriptor. Log messages written to this file descriptor as simple
       newline-separated text strings are written to the journal. This file descriptor can be used internally by applications or be made
       STDOUT/STDERR of other processes executed.

       sd_journal_stream_fd() takes a short program identifier string as first argument, which will be written to the journal as
       _SYSLOG_IDENTIFIER= field for each log entry (see systemd.journal-fields(7) for more information). The second argument shall be the default
       priority level for all messages. The priority level is one of LOG_EMERG, LOG_ALERT, LOG_CRIT, LOG_ERR, LOG_WARNING, LOG_NOTICE, LOG_INFO,
       LOG_DEBUG, as defined in syslog.h, see syslog(3) for details. The third argument is a boolean: if true kernel-style log priority level
       prefixes (such as SD_WARNING) are interpreted, see sd-daemon(3) for more information.

       It is recommended that applications log UTF-8 messages only with this API, but this is not enforced.

RETURN VALUE

       The call returns a valid write-only file descriptor on success or a negative errno-style error code.

NOTES

       The sd_journal_stream_fd() interface is available as a shared library, which can be compiled and linked to with the libsystemd-journal pkg-
       config(1) file.

EXAMPLES

       Creating a log stream suitable for fprintf(3):

	   #include <syslog.h>
	   #include <stdio.h>
	   #include <string.h>
	   #include <unistd.h>
	   #include <systemd/sd-journal.h>
	   #include <systemd/sd-daemon.h>

	   int main(int argc, char *argv[]) {
		   int fd;
		   FILE *log;
		   fd = sd_journal_stream_fd("test", LOG_INFO, 1);
		   if (fd < 0) {
			   fprintf(stderr, "Failed to create stream fd: %s
", strerror(-fd));
			   return 1;
		   }
		   log = fdopen(fd, "w");
		   if (!log) {
			   fprintf(stderr, "Failed to create file object: %m
");
			   close(fd);
			   return 1;
		   }
		   fprintf(log, "Hello World!
");
		   fprintf(log, SD_WARNING "This is a warning!
");
		   fclose(log);
		   return 0;
	   }

SEE ALSO

       systemd(1), sd-journal(3), sd-daemon(3), sd_journal_print(3), syslog(3), fprintf(3), systemd.journal-fields(7)

systemd 208														   SD_JOURNAL_STREAM_FD(3)