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Diffstat (limited to 'man/sd_journal_print.xml')
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diff --git a/man/sd_journal_print.xml b/man/sd_journal_print.xml index 055094c9a2..068b10e7ca 100644 --- a/man/sd_journal_print.xml +++ b/man/sd_journal_print.xml @@ -1,6 +1,6 @@ <?xml version='1.0'?> <!--*-nxml-*--> <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" - "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> + "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> <!-- This file is part of systemd. @@ -23,248 +23,238 @@ <refentry id="sd_journal_print"> - <refentryinfo> - <title>sd_journal_print</title> - <productname>systemd</productname> - - <authorgroup> - <author> - <contrib>Developer</contrib> - <firstname>Lennart</firstname> - <surname>Poettering</surname> - <email>lennart@poettering.net</email> - </author> - </authorgroup> - </refentryinfo> - - <refmeta> - <refentrytitle>sd_journal_print</refentrytitle> - <manvolnum>3</manvolnum> - </refmeta> - - <refnamediv> - <refname>sd_journal_print</refname> - <refname>sd_journal_printv</refname> - <refname>sd_journal_send</refname> - <refname>sd_journal_sendv</refname> - <refname>sd_journal_perror</refname> - <refname>SD_JOURNAL_SUPPRESS_LOCATION</refname> - <refpurpose>Submit log entries to the journal</refpurpose> - </refnamediv> - - <refsynopsisdiv> - <funcsynopsis> - <funcsynopsisinfo>#include <systemd/sd-journal.h></funcsynopsisinfo> - - <funcprototype> - <funcdef>int <function>sd_journal_print</function></funcdef> - <paramdef>int <parameter>priority</parameter></paramdef> - <paramdef>const char *<parameter>format</parameter></paramdef> - <paramdef>...</paramdef> - </funcprototype> - - <funcprototype> - <funcdef>int <function>sd_journal_printv</function></funcdef> - <paramdef>int <parameter>priority</parameter></paramdef> - <paramdef>const char *<parameter>format</parameter></paramdef> - <paramdef>va_list <parameter>ap</parameter></paramdef> - </funcprototype> - - <funcprototype> - <funcdef>int <function>sd_journal_send</function></funcdef> - <paramdef>const char *<parameter>format</parameter></paramdef> - <paramdef>...</paramdef> - </funcprototype> - - <funcprototype> - <funcdef>int <function>sd_journal_sendv</function></funcdef> - <paramdef>const struct iovec *<parameter>iov</parameter></paramdef> - <paramdef>int <parameter>n</parameter></paramdef> - </funcprototype> - - <funcprototype> - <funcdef>int <function>sd_journal_perror</function></funcdef> - <paramdef>const char *<parameter>message</parameter></paramdef> - </funcprototype> - - </funcsynopsis> - </refsynopsisdiv> - - <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 - <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> - - <para><function>sd_journal_printv()</function> is - similar to <function>sd_journal_print()</function> but - takes a variable argument list encapsulated in an - object of type <varname>va_list</varname> (see - <citerefentry><refentrytitle>stdarg</refentrytitle><manvolnum>3</manvolnum></citerefentry> - 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><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_perror()</function> is a - similar to - <citerefentry><refentrytitle>perror</refentrytitle><manvolnum>3</manvolnum></citerefentry> - and writes a message to the journal that consists of - the passed string, suffixed with ": " and a human - readable representation of the current error code - stored in - <citerefentry project='man-pages'><refentrytitle>errno</refentrytitle><manvolnum>3</manvolnum></citerefentry>. If - the message string is passed as <constant>NULL</constant> or empty string, - only the error string representation will be written, - prefixed with nothing. An additional journal field - ERRNO= is included in the entry containing the numeric - error code formatted as decimal string. The log - priority used is <constant>LOG_ERR</constant> (3).</para> - - <para>Note that <function>sd_journal_send()</function> - is a wrapper around - <function>sd_journal_sendv()</function> to make it - easier to use when only text strings shall be - submitted. Also, the following two calls are - mostly equivalent:</para> - - <programlisting>sd_journal_print(LOG_INFO, "Hello World, this is PID %lu!", (unsigned long) getpid()); + <refentryinfo> + <title>sd_journal_print</title> + <productname>systemd</productname> + + <authorgroup> + <author> + <contrib>Developer</contrib> + <firstname>Lennart</firstname> + <surname>Poettering</surname> + <email>lennart@poettering.net</email> + </author> + </authorgroup> + </refentryinfo> + + <refmeta> + <refentrytitle>sd_journal_print</refentrytitle> + <manvolnum>3</manvolnum> + </refmeta> + + <refnamediv> + <refname>sd_journal_print</refname> + <refname>sd_journal_printv</refname> + <refname>sd_journal_send</refname> + <refname>sd_journal_sendv</refname> + <refname>sd_journal_perror</refname> + <refname>SD_JOURNAL_SUPPRESS_LOCATION</refname> + <refpurpose>Submit log entries to the journal</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <funcsynopsis> + <funcsynopsisinfo>#include <systemd/sd-journal.h></funcsynopsisinfo> + + <funcprototype> + <funcdef>int <function>sd_journal_print</function></funcdef> + <paramdef>int <parameter>priority</parameter></paramdef> + <paramdef>const char *<parameter>format</parameter></paramdef> + <paramdef>...</paramdef> + </funcprototype> + + <funcprototype> + <funcdef>int <function>sd_journal_printv</function></funcdef> + <paramdef>int <parameter>priority</parameter></paramdef> + <paramdef>const char *<parameter>format</parameter></paramdef> + <paramdef>va_list <parameter>ap</parameter></paramdef> + </funcprototype> + + <funcprototype> + <funcdef>int <function>sd_journal_send</function></funcdef> + <paramdef>const char *<parameter>format</parameter></paramdef> + <paramdef>...</paramdef> + </funcprototype> + + <funcprototype> + <funcdef>int <function>sd_journal_sendv</function></funcdef> + <paramdef>const struct iovec *<parameter>iov</parameter></paramdef> + <paramdef>int <parameter>n</parameter></paramdef> + </funcprototype> + + <funcprototype> + <funcdef>int <function>sd_journal_perror</function></funcdef> + <paramdef>const char *<parameter>message</parameter></paramdef> + </funcprototype> + + </funcsynopsis> + </refsynopsisdiv> + + <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 + <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> + + <para><function>sd_journal_printv()</function> is similar to + <function>sd_journal_print()</function> but takes a variable + argument list encapsulated in an object of type + <varname>va_list</varname> (see + <citerefentry><refentrytitle>stdarg</refentrytitle><manvolnum>3</manvolnum></citerefentry> + 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><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_perror()</function> is a similar to + <citerefentry><refentrytitle>perror</refentrytitle><manvolnum>3</manvolnum></citerefentry> + and writes a message to the journal that consists of the passed + string, suffixed with ": " and a human readable representation of + the current error code stored in + <citerefentry project='man-pages'><refentrytitle>errno</refentrytitle><manvolnum>3</manvolnum></citerefentry>. + If the message string is passed as <constant>NULL</constant> or + empty string, only the error string representation will be + written, prefixed with nothing. An additional journal field ERRNO= + is included in the entry containing the numeric error code + formatted as decimal string. The log priority used is + <constant>LOG_ERR</constant> (3).</para> + + <para>Note that <function>sd_journal_send()</function> is a + wrapper around <function>sd_journal_sendv()</function> to make it + easier to use when only text strings shall be submitted. Also, the + following two calls are mostly equivalent:</para> + + <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> - - <para>Note that these calls implicitly add fields for - the source file, function name and code line where - invoked. This is implemented with macros. If this is - not desired, it can be turned off by defining - SD_JOURNAL_SUPPRESS_LOCATION before including - <filename>sd-journal.h</filename>.</para> - - <para><citerefentry project='man-pages'><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry> - and <function>sd_journal_print()</function> may - largely be used interchangeably - functionality-wise. However, note that log messages - logged via the former take a different path to the - journal server than the later, and hence global - chronological ordering between the two streams cannot - be guaranteed. Using - <function>sd_journal_print()</function> has the - benefit of logging source code line, filenames, and - functions as metadata along all entries, and - guaranteeing chronological ordering with structured - log entries that are generated via - <function>sd_journal_send()</function>. Using - <function>syslog()</function> has the benefit of being - more portable.</para> - </refsect1> - - <refsect1> - <title>Return Value</title> - - <para>The four calls return 0 on success or a negative - errno-style error code. The - <citerefentry project='man-pages'><refentrytitle>errno</refentrytitle><manvolnum>3</manvolnum></citerefentry> - variable itself is not altered.</para> - - <para>If - <citerefentry><refentrytitle>systemd-journald</refentrytitle><manvolnum>8</manvolnum></citerefentry> - is not running (the socket is not present), those - functions do nothing, and also return 0.</para> - </refsect1> - - <refsect1> - <title>Async signal safety</title> - <para><function>sd_journal_sendv()</function> is "async signal - safe" in the meaning of <citerefentry><refentrytitle>signal</refentrytitle><manvolnum>7</manvolnum></citerefentry>. - </para> - - <para><function>sd_journal_print</function>, - <function>sd_journal_printv</function>, - <function>sd_journal_send</function>, and - <function>sd_journal_perror</function> are - not async signal safe.</para> - </refsect1> - - <refsect1> - <title>Notes</title> - - <para>The <function>sd_journal_print()</function>, - <function>sd_journal_printv()</function>, - <function>sd_journal_send()</function> and - <function>sd_journal_sendv()</function> interfaces - are available as a shared library, which can be compiled - and linked to with the - <constant>libsystemd</constant> <citerefentry project='die-net'><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry> - file.</para> - </refsect1> - - <refsect1> - <title>See Also</title> - - <para> - <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd-journal</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd_journal_stream_fd</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry project='man-pages'><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>perror</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry project='man-pages'><refentrytitle>errno</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>, - <citerefentry><refentrytitle>signal</refentrytitle><manvolnum>7</manvolnum></citerefentry>, - <citerefentry><refentrytitle>socket</refentrytitle><manvolnum>7</manvolnum></citerefentry> - </para> - </refsect1> + "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 + implemented with macros. If this is not desired, it can be turned + off by defining SD_JOURNAL_SUPPRESS_LOCATION before including + <filename>sd-journal.h</filename>.</para> + + <para><citerefentry project='man-pages'><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry> + and <function>sd_journal_print()</function> may + largely be used interchangeably + functionality-wise. However, note that log messages + logged via the former take a different path to the + journal server than the later, and hence global + chronological ordering between the two streams cannot + be guaranteed. Using + <function>sd_journal_print()</function> has the + benefit of logging source code line, filenames, and + functions as metadata along all entries, and + guaranteeing chronological ordering with structured + log entries that are generated via + <function>sd_journal_send()</function>. Using + <function>syslog()</function> has the benefit of being + more portable.</para> + </refsect1> + + <refsect1> + <title>Return Value</title> + + <para>The four calls return 0 on success or a negative errno-style + error code. The + <citerefentry project='man-pages'><refentrytitle>errno</refentrytitle><manvolnum>3</manvolnum></citerefentry> + variable itself is not altered.</para> + + <para>If + <citerefentry><refentrytitle>systemd-journald</refentrytitle><manvolnum>8</manvolnum></citerefentry> + is not running (the socket is not present), those functions do + nothing, and also return 0.</para> + </refsect1> + + <refsect1> + <title>Async signal safety</title> + <para><function>sd_journal_sendv()</function> is "async signal + safe" in the meaning of + <citerefentry><refentrytitle>signal</refentrytitle><manvolnum>7</manvolnum></citerefentry>. + </para> + + <para><function>sd_journal_print</function>, + <function>sd_journal_printv</function>, + <function>sd_journal_send</function>, and + <function>sd_journal_perror</function> are + not async signal safe.</para> + </refsect1> + + <refsect1> + <title>Notes</title> + + <para>The <function>sd_journal_print()</function>, + <function>sd_journal_printv()</function>, + <function>sd_journal_send()</function> and + <function>sd_journal_sendv()</function> interfaces are available + as a shared library, which can be compiled and linked to with the + <constant>libsystemd</constant> <citerefentry project='die-net'><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry> + file.</para> + </refsect1> + + <refsect1> + <title>See Also</title> + + <para> + <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd-journal</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_journal_stream_fd</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry project='man-pages'><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>perror</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry project='man-pages'><refentrytitle>errno</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>, + <citerefentry><refentrytitle>signal</refentrytitle><manvolnum>7</manvolnum></citerefentry>, + <citerefentry><refentrytitle>socket</refentrytitle><manvolnum>7</manvolnum></citerefentry> + </para> + </refsect1> </refentry> |