diff options
Diffstat (limited to 'man/sd_journal_get_cursor.xml')
| -rw-r--r-- | man/sd_journal_get_cursor.xml | 53 |
1 files changed, 41 insertions, 12 deletions
diff --git a/man/sd_journal_get_cursor.xml b/man/sd_journal_get_cursor.xml index 9e00ef7c82..354168bee2 100644 --- a/man/sd_journal_get_cursor.xml +++ b/man/sd_journal_get_cursor.xml @@ -44,7 +44,8 @@ <refnamediv> <refname>sd_journal_get_cursor</refname> - <refpurpose>Get cursor string for the current journal entry</refpurpose> + <refname>sd_journal_test_cursor</refname> + <refpurpose>Get cursor string for or test cursor string against the current journal entry</refpurpose> </refnamediv> <refsynopsisdiv> @@ -57,6 +58,12 @@ <paramdef>char ** <parameter>cursor</parameter></paramdef> </funcprototype> + <funcprototype> + <funcdef>int <function>sd_journal_test_cursor</function></funcdef> + <paramdef>sd_journal* <parameter>j</parameter></paramdef> + <paramdef>const char * <parameter>cursor</parameter></paramdef> + </funcprototype> + </funcsynopsis> </refsynopsisdiv> @@ -66,7 +73,7 @@ <para><function>sd_journal_get_cursor()</function> returns a cursor string for the current journal entry. A cursor is a serialization of the current - journal position in text form. The string only + journal position formatted as text. The string only contains printable characters and can be passed around in text form. The cursor identifies a journal entry globally and in a stable way and may be used to later @@ -77,16 +84,33 @@ without the specific entry being available locally will seek to the next closest (in terms of time) available entry. The call takes two arguments: a - journal context object and a pointer to a - string pointer where the cursor string will be - placed. The string is allocated via libc <citerefentry><refentrytitle>malloc</refentrytitle><manvolnum>3</manvolnum></citerefentry> and should - be freed after use with + journal context object and a pointer to a string + pointer where the cursor string will be placed. The + string is allocated via libc + <citerefentry><refentrytitle>malloc</refentrytitle><manvolnum>3</manvolnum></citerefentry> + and should be freed after use with <citerefentry><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para> - <para>Note that this function will not work before + <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> + (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 + useful since cursor strings do not uniquely identify + an entry: the same entry might be referred to by + 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> + whether the entry being seeked to was actually found + in the journal or the next closest entry was used + instead.</para> </refsect1> <refsect1> @@ -94,15 +118,20 @@ <para><function>sd_journal_get_cursor()</function> returns 0 on success or a negative errno-style error - code.</para> + code. <function>sd_journal_test_cursor()</function> + returns positive if the current entry matches the + specified cursor, 0 if it doesn't match the specified + cursor or a negative errno-style error code on + failure.</para> </refsect1> <refsect1> <title>Notes</title> <para>The <function>sd_journal_get_cursor()</function> - interface is available as shared library, which can be - compiled and linked to with the + and <function>sd_journal_test_cursor()</function> + interfaces are available as shared library, which can + be compiled and linked to with the <literal>libsystemd-journal</literal> <citerefentry><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry> file.</para> |