|
NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | NOTES | SEE ALSO | COLOPHON |
SD_JOURNAL_SEEK_HEAD(3) sd_journal_seek_head SD_JOURNAL_SEEK_HEAD(3)
sd_journal_seek_head, sd_journal_seek_tail,
sd_journal_seek_monotonic_usec, sd_journal_seek_realtime_usec,
sd_journal_seek_cursor - Seek to a position in the journal
#include <systemd/sd-journal.h>
int sd_journal_seek_head(sd_journal *j);
int sd_journal_seek_tail(sd_journal *j);
int sd_journal_seek_monotonic_usec(sd_journal *j, sd_id128_t boot_id,
uint64_t usec);
int sd_journal_seek_realtime_usec(sd_journal *j, uint64_t usec);
int sd_journal_seek_cursor(sd_journal *j, const char *cursor);
sd_journal_seek_head() seeks to the beginning of the journal, i.e.
the oldest available entry.
Similarly, sd_journal_seek_tail() may be used to seek to the end of
the journal, i.e. the most recent available entry.
sd_journal_seek_monotonic_usec() seeks to the entry with the
specified monotonic timestamp, i.e. CLOCK_MONOTONIC. Since monotonic
time restarts on every reboot a boot ID needs to be specified as
well.
sd_journal_seek_realtime_usec() seeks to the entry with the specified
realtime (wallclock) timestamp, i.e. CLOCK_REALTIME. Note that the
realtime clock is not necessarily monotonic. If a realtime timestamp
is ambiguous, it is not defined which position is sought to.
sd_journal_seek_cursor() seeks to the entry located at the specified
cursor string. For details on cursors, see sd_journal_get_cursor(3).
If no entry matching the specified cursor is found the call will seek
to the next closest entry (in terms of time) instead. To verify
whether the newly selected entry actually matches the cursor, use
sd_journal_test_cursor(3).
Note that these calls do not actually make any entry the new current
entry, this needs to be done in a separate step with a subsequent
sd_journal_next(3) invocation (or a similar call). Only then, entry
data may be retrieved via sd_journal_get_data(3). If no entry exists
that matches exactly the specified seek address, the next closest is
sought to. If sd_journal_next(3) is used, the closest following entry
will be sought to, if sd_journal_previous(3) is used the closest
preceding entry is sought to.
The functions return 0 on success or a negative errno-style error
code.
All functions listed here are thread-agnostic and only a single
thread may operate on a given sd_journal object.
The sd_journal_seek_head(), sd_journal_seek_tail(),
sd_journal_seek_monotonic_usec(), sd_journal_seek_realtime_usec(),
and sd_journal_seek_cursor() interfaces are available as a shared
library, which can be compiled and linked to with the
libsystemd pkg-config(1) file.
systemd(1), sd-journal(3), sd_journal_open(3), sd_journal_next(3),
sd_journal_get_data(3), sd_journal_get_cursor(3),
sd_journal_get_realtime_usec(3)
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
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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 234 SD_JOURNAL_SEEK_HEAD(3)
Pages that refer to this page: sd-journal(3), sd_journal_get_cursor(3), sd_journal_next(3), sd_journal_open(3), systemd.directives(7), systemd.index(7)