sd-journal(3)

NAME

   sd-journal - APIs for submitting and querying log entries to and from
   the journal

SYNOPSIS

   #include <systemd/sd-journal.h>

   pkg-config --cflags --libs libsystemd

DESCRIPTION

   sd-journal.h provides APIs to submit and query log entries. The APIs
   exposed act both as client for the systemd-journald.service(8) journal
   service and as parser for the journal files on disk.

   See sd_journal_print(3), sd_journal_stream_fd(3), sd_journal_open(3),
   sd_journal_next(3), sd_journal_get_realtime_usec(3),
   sd_journal_add_match(3), sd_journal_seek_head(3),
   sd_journal_enumerate_fields(3), sd_journal_get_cursor(3),
   sd_journal_get_cutoff_realtime_usec(3),
   sd_journal_get_cutoff_monotonic_usec(3), sd_journal_get_usage(3),
   sd_journal_get_catalog(3), sd_journal_get_fd(3),
   sd_journal_has_runtime_files(3) and sd_journal_has_persistent_files(3)
   for more information about the functions implemented.

   Command line access for submitting entries to the journal is available
   with the systemd-cat(1) tool. Command line access for querying entries
   from the journal is available with the journalctl(1) tool.

THREAD SAFETY

   Functions that operate on the sd_journal object are thread agnostic ---
   given sd_journal pointer may only be used from one thread at a time,
   but multiple threads may use multiple such objects safely. Other
   functions --- those that are used to send entries to the journal, like
   sd_journal_print(3) and similar, or those that are used to retrieve
   global information like sd_journal_stream_fd(3) and
   sd_journal_get_catalog_for_message_id(3) --- are thread-safe and may be
   called from multiple threads in parallel.

NOTES

   These APIs are implemented as a shared library, which can be compiled
   and linked to with the libsystemd pkg-config(1) file.

SEE ALSO

   systemd(1), sd_journal_print(3), sd_journal_stream_fd(3),
   sd_journal_open(3), sd_journal_next(3), sd_journal_get_data(3),
   sd_journal_get_realtime_usec(3), sd_journal_add_match(3),
   sd_journal_seek_head(3), sd_journal_enumerate_fields(3),
   sd_journal_get_cursor(3), sd_journal_get_cutoff_realtime_usec(3),
   sd_journal_get_cutoff_monotonic_usec(3), sd_journal_get_usage(3),
   sd_journal_get_fd(3), sd_journal_query_unique(3),
   sd_journal_get_catalog(3), sd_journal_has_runtime_files(3),
   sd_journal_has_persistent_files(3), journalctl(1), sd-id128(3), pkg-
   config(1)

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