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 sd_journal objects are thread agnostic — given sd_journal
       pointer may only be used from one specific thread at all times (and it has to be the very
       same one during the entire lifetime of the object), but multiple, independent threads may
       use multiple, independent 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 fully 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)