man7.org > Linux > man-pages

Linux/UNIX system programming training

sd_journal_get_usage(3) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | NOTES | HISTORY | SEE ALSO | COLOPHON 

SD_JOURNAL_GET_USAGE(3)    sd_journal_get_usage   SD_JOURNAL_GET_USAGE(3)

NAME         top

       sd_journal_get_usage - Journal disk usage

SYNOPSIS         top

       #include <systemd/sd-journal.h>

       int sd_journal_get_usage(sd_journal *j, uint64_t *bytes);

DESCRIPTION         top

       sd_journal_get_usage() determines the total disk space currently
       used by journal files (in bytes). If SD_JOURNAL_LOCAL_ONLY was
       passed when opening the journal, this value will only reflect the
       size of journal files of the local host, otherwise of all hosts.

RETURN VALUE         top

       sd_journal_get_usage() returns 0 on success or a negative
       errno-style error code.

NOTES         top

       All functions listed here are thread-agnostic and only a single
       thread may operate on a given object at any given time. Different
       threads may access the same object at different times. Multiple
       independent objects may be used from different threads in
       parallel.

       Functions described here are available as a shared library, which
       can be compiled against and linked to with the
       libsystemd pkg-config(1) file.

HISTORY         top

       sd_journal_get_usage() was added in version 190.

SEE ALSO         top

       systemd(1), sd-journal(3), sd_journal_open(3)

COLOPHON         top

       This page is part of the systemd (systemd system and service
       manager) project.  Information about the project can be found at
       ⟨http://www.freedesktop.org/wiki/Software/systemd⟩.  If you have a
       bug report for this manual page, see
       ⟨http://www.freedesktop.org/wiki/Software/systemd/#bugreports⟩.
       This page was obtained from the project's upstream Git repository
       ⟨https://github.com/systemd/systemd.git⟩ on 2026-01-16.  (At that
       time, the date of the most recent commit that was found in the
       repository was 2026-01-16.)  If you discover any rendering
       problems in this HTML version of the page, or you believe there is
       a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to
       man-pages@man7.org

systemd 260~devel                                 SD_JOURNAL_GET_USAGE(3)

Pages that refer to this page: sd-journal(3),  systemd.directives(7),  systemd.index(7)

HTML rendering created 2026-01-16 by Michael Kerrisk, author of The Linux Programming Interface.

For details of in-depth Linux/UNIX system programming training courses that I teach, look here.

Hosting by jambit GmbH.

Cover of TLPI