1SD_JOURNAL_SEEK_HEAD(3)      sd_journal_seek_head      SD_JOURNAL_SEEK_HEAD(3)
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NAME

6       sd_journal_seek_head, sd_journal_seek_tail,
7       sd_journal_seek_monotonic_usec, sd_journal_seek_realtime_usec,
8       sd_journal_seek_cursor - Seek to a position in the journal
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SYNOPSIS

11       #include <systemd/sd-journal.h>
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13       int sd_journal_seek_head(sd_journal *j);
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15       int sd_journal_seek_tail(sd_journal *j);
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17       int sd_journal_seek_monotonic_usec(sd_journal *j, sd_id128_t boot_id,
18                                          uint64_t usec);
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20       int sd_journal_seek_realtime_usec(sd_journal *j, uint64_t usec);
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22       int sd_journal_seek_cursor(sd_journal *j, const char *cursor);
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DESCRIPTION

25       sd_journal_seek_head() seeks to the beginning of the journal, i.e. the
26       oldest available entry.
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28       Similarly, sd_journal_seek_tail() may be used to seek to the end of the
29       journal, i.e. the most recent available entry.
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31       sd_journal_seek_monotonic_usec() seeks to the entry with the specified
32       monotonic timestamp, i.e.  CLOCK_MONOTONIC. Since monotonic time
33       restarts on every reboot a boot ID needs to be specified as well.
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35       sd_journal_seek_realtime_usec() seeks to the entry with the specified
36       realtime (wallclock) timestamp, i.e.  CLOCK_REALTIME. Note that the
37       realtime clock is not necessarily monotonic. If a realtime timestamp is
38       ambiguous, it is not defined which position is sought to.
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40       sd_journal_seek_cursor() seeks to the entry located at the specified
41       cursor string. For details on cursors, see sd_journal_get_cursor(3). If
42       no entry matching the specified cursor is found the call will seek to
43       the next closest entry (in terms of time) instead. To verify whether
44       the newly selected entry actually matches the cursor, use
45       sd_journal_test_cursor(3).
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47       Note that these calls do not actually make any entry the new current
48       entry, this needs to be done in a separate step with a subsequent
49       sd_journal_next(3) invocation (or a similar call). Only then, entry
50       data may be retrieved via sd_journal_get_data(3). If no entry exists
51       that matches exactly the specified seek address, the next closest is
52       sought to. If sd_journal_next(3) is used, the closest following entry
53       will be sought to, if sd_journal_previous(3) is used the closest
54       preceding entry is sought to.
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RETURN VALUE

57       The functions return 0 on success or a negative errno-style error code.
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NOTES

60       The sd_journal_seek_head(), sd_journal_seek_tail(),
61       sd_journal_seek_monotonic_usec(), sd_journal_seek_realtime_usec(), and
62       sd_journal_seek_cursor() interfaces are available as a shared library,
63       which can be compiled and linked to with the libsystemd pkg-config(1)
64       file.
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SEE ALSO

67       systemd(1), sd-journal(3), sd_journal_open(3), sd_journal_next(3),
68       sd_journal_get_data(3), sd_journal_get_cursor(3),
69       sd_journal_get_realtime_usec(3)
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73systemd 219                                            SD_JOURNAL_SEEK_HEAD(3)
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