man: mention that sd_journal_test_cursor() needs a positioning call

Fixes #30331.
This commit is contained in:
Zbigniew Jędrzejewski-Szmek 2024-04-17 18:11:31 +02:00 committed by Lennart Poettering
parent 617a2be0d5
commit aea6787f78
2 changed files with 16 additions and 9 deletions

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@ -61,12 +61,6 @@
and should be freed after use with
<citerefentry project='man-pages'><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para>
<para>Note that <function>sd_journal_get_cursor()</function> will
not work before
<citerefentry><refentrytitle>sd_journal_next</refentrytitle><manvolnum>3</manvolnum></citerefentry>
(or related call) has been called at least once, in order to
position the read pointer at a valid entry.</para>
<para><function>sd_journal_test_cursor()</function>
may be used to check whether the current position in
the journal matches the specified cursor. This is
@ -75,10 +69,17 @@
multiple different cursor strings, and hence string
comparing cursors is not possible. Use this call to
verify after an invocation of
<citerefentry><refentrytitle>sd_journal_seek_cursor</refentrytitle><manvolnum>3</manvolnum></citerefentry>
<citerefentry><refentrytitle>sd_journal_seek_cursor</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
whether the entry being sought to was actually found
in the journal or the next closest entry was used
instead.</para>
<para>Note that <function>sd_journal_get_cursor()</function>
and <function>sd_journal_test_cursor()</function>
will not work before
<citerefentry><refentrytitle>sd_journal_next</refentrytitle><manvolnum>3</manvolnum></citerefentry>
(or one of the other functions which move to an entry)
has been called at least once to position the read pointer at a valid entry.</para>
</refsect1>
<refsect1>

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@ -82,8 +82,7 @@
string. For details on cursors, see
<citerefentry><refentrytitle>sd_journal_get_cursor</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
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
<citerefentry><refentrytitle>sd_journal_test_cursor</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para>
of time) instead.</para>
<para>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
@ -97,6 +96,13 @@
used, the closest following entry will be sought to, if
<citerefentry><refentrytitle>sd_journal_previous</refentrytitle><manvolnum>3</manvolnum></citerefentry>
is used the closest preceding entry is sought to.</para>
<para>After the seek is done, and
<citerefentry><refentrytitle>sd_journal_next</refentrytitle><manvolnum>3</manvolnum></citerefentry>
or a similar call has been made,
<citerefentry><refentrytitle>sd_journal_test_cursor</refentrytitle><manvolnum>3</manvolnum></citerefentry>
may be used to verify whether the newly selected entry actually matches the cursor.
</para>
</refsect1>
<refsect1>