man/journal-iterate-unique.c

   1 /* SPDX-License-Identifier: CC0-1.0 */
   2
   3 #include <errno.h>
   4 #include <stdio.h>
   5 #include <systemd/sd-journal.h>
   6
   7 int main(int argc, char *argv[]) {
   8   sd_journal *j;
   9   const void *d;
  10   size_t l;
  11   int r;
  12
  13   r = sd_journal_open(&j, SD_JOURNAL_LOCAL_ONLY);
  14   if (r < 0) {
  15     errno = -r;
  16     fprintf(stderr, "Failed to open journal: %m\n");
  17     return 1;
  18   }
  19   r = sd_journal_query_unique(j, "_SYSTEMD_UNIT");
  20   if (r < 0) {
  21     errno = -r;
  22     fprintf(stderr, "Failed to query journal: %m\n");
  23     return 1;
  24   }
  25   SD_JOURNAL_FOREACH_UNIQUE(j, d, l)
  26     printf("%.*s\n", (int) l, (const char*) d);
  27   sd_journal_close(j);
  28   return 0;
  29 }