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Diffstat (limited to 'man/sd_journal_print.xml')
| -rw-r--r-- | man/sd_journal_print.xml | 87 |
1 files changed, 36 insertions, 51 deletions
diff --git a/man/sd_journal_print.xml b/man/sd_journal_print.xml index 17fdc9c1f2..76542527fc 100644 --- a/man/sd_journal_print.xml +++ b/man/sd_journal_print.xml @@ -93,27 +93,21 @@ <refsect1> <title>Description</title> - <para><function>sd_journal_print()</function> may be used to - submit simple, plain text log entries to the system journal. The - first argument is a priority value. This is followed by a format - string and its parameters, similar to - <citerefentry project='man-pages'><refentrytitle>printf</refentrytitle><manvolnum>3</manvolnum></citerefentry> - or + <para><function>sd_journal_print()</function> may be used to submit simple, plain text log entries to the system + journal. The first argument is a priority value. This is followed by a format string and its parameters, similar to + <citerefentry project='man-pages'><refentrytitle>printf</refentrytitle><manvolnum>3</manvolnum></citerefentry> or <citerefentry project='man-pages'><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>. - The priority value is one of - <constant>LOG_EMERG</constant>, - <constant>LOG_ALERT</constant>, - <constant>LOG_CRIT</constant>, - <constant>LOG_ERR</constant>, - <constant>LOG_WARNING</constant>, - <constant>LOG_NOTICE</constant>, - <constant>LOG_INFO</constant>, - <constant>LOG_DEBUG</constant>, as defined in - <filename>syslog.h</filename>, see - <citerefentry project='man-pages'><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry> - for details. It is recommended to use this call to submit log - messages in the application locale or system locale and in UTF-8 - format, but no such restrictions are enforced.</para> + The priority value is one of <constant>LOG_EMERG</constant>, <constant>LOG_ALERT</constant>, + <constant>LOG_CRIT</constant>, <constant>LOG_ERR</constant>, <constant>LOG_WARNING</constant>, + <constant>LOG_NOTICE</constant>, <constant>LOG_INFO</constant>, <constant>LOG_DEBUG</constant>, as defined in + <filename>syslog.h</filename>, see <citerefentry + project='man-pages'><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry> for details. It is + recommended to use this call to submit log messages in the application locale or system locale and in UTF-8 format, + but no such restrictions are enforced. Note that log messages written using this function are generally not + expected to end in a new-line character. However, as all trailing whitespace (including spaces, new-lines, + tabulators and carriage returns) are automatically stripped from the logged string, it is acceptable to specify one + (or more). Empty lines (after trailing whitespace removal) are suppressed. On non-empty lines, leading whitespace + (as well as inner whitespace) is left unmodified. </para> <para><function>sd_journal_printv()</function> is similar to <function>sd_journal_print()</function> but takes a variable @@ -123,35 +117,26 @@ for more information) instead of the format string. It is otherwise equivalent in behavior.</para> - <para><function>sd_journal_send()</function> may be used to submit - structured log entries to the system journal. It takes a series of - format strings, each immediately followed by their associated - parameters, terminated by <constant>NULL</constant>. The strings - passed should be of the format <literal>VARIABLE=value</literal>. - The variable name must be in uppercase and consist only of - characters, numbers and underscores, and may not begin with an - underscore. (All assignments that do not follow this syntax will - be ignored.) The value can be of any size and format. It is highly - recommended to submit text strings formatted in the UTF-8 - character encoding only, and submit binary fields only when - formatting in UTF-8 strings is not sensible. A number of - well-known fields are defined, see - <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry> - for details, but additional application defined fields may be - used. A variable may be assigned more than one value per - entry.</para> - - <para><function>sd_journal_sendv()</function> is similar to - <function>sd_journal_send()</function> but takes an array of - <varname>struct iovec</varname> (as defined in - <filename>uio.h</filename>, see - <citerefentry project='man-pages'><refentrytitle>readv</refentrytitle><manvolnum>3</manvolnum></citerefentry> - for details) instead of the format string. Each structure should - reference one field of the entry to submit. The second argument - specifies the number of structures in the array. - <function>sd_journal_sendv()</function> is particularly useful to - submit binary objects to the journal where that is - necessary.</para> + <para><function>sd_journal_send()</function> may be used to submit structured log entries to the system journal. It + takes a series of format strings, each immediately followed by their associated parameters, terminated by + <constant>NULL</constant>. The strings passed should be of the format <literal>VARIABLE=value</literal>. The + variable name must be in uppercase and consist only of characters, numbers and underscores, and may not begin with + an underscore. (All assignments that do not follow this syntax will be ignored.) The value can be of any size and + format. It is highly recommended to submit text strings formatted in the UTF-8 character encoding only, and submit + binary fields only when formatting in UTF-8 strings is not sensible. A number of well-known fields are defined, see + <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry> for + details, but additional application defined fields may be used. A variable may be assigned more than one value per + entry. If this function is used, trailing whitespace is automatically removed from each formatted field.</para> + + <para><function>sd_journal_sendv()</function> is similar to <function>sd_journal_send()</function> but takes an + array of <varname>struct iovec</varname> (as defined in <filename>uio.h</filename>, see <citerefentry + project='man-pages'><refentrytitle>readv</refentrytitle><manvolnum>3</manvolnum></citerefentry> for details) + instead of the format string. Each structure should reference one field of the entry to submit. The second argument + specifies the number of structures in the array. <function>sd_journal_sendv()</function> is particularly useful to + submit binary objects to the journal where that is necessary. Note that this function wil not strip trailing + whitespace of the passed fields, but passes the specified data along unmodified. This is different from both + <function>sd_journal_print()</function> and <function>sd_journal_send()</function> described above, which are based + on format strings, and do strip trailing whitespace.</para> <para><function>sd_journal_perror()</function> is a similar to <citerefentry project='die-net'><refentrytitle>perror</refentrytitle><manvolnum>3</manvolnum></citerefentry> @@ -174,8 +159,8 @@ <programlisting>sd_journal_print(LOG_INFO, "Hello World, this is PID %lu!", (unsigned long) getpid()); sd_journal_send("MESSAGE=Hello World, this is PID %lu!", (unsigned long) getpid(), - "PRIORITY=%i", LOG_INFO, - NULL);</programlisting> + "PRIORITY=%i", LOG_INFO, + NULL);</programlisting> <para>Note that these calls implicitly add fields for the source file, function name and code line where invoked. This is |