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)

systemd 249                                                                                        SD-JOURNAL(3)