chiark / gitweb /
namespace: include boot id in private tmp directories
[elogind.git] / man / sd_journal_print.xml
index 65694a2..e61a648 100644 (file)
@@ -47,6 +47,8 @@
                 <refname>sd_journal_printv</refname>
                 <refname>sd_journal_send</refname>
                 <refname>sd_journal_sendv</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>
 
                 <refpurpose>Submit log entries to the journal</refpurpose>
         </refnamediv>
 
                                 <paramdef>int <parameter>n</parameter></paramdef>
                         </funcprototype>
 
                                 <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>
 
                 </funcsynopsis>
         </refsynopsisdiv>
 
                 or
                 <citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>. The
                 priority value is one of
                 or
                 <citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>. The
                 priority value is one of
-                <literal>LOG_EMERG</literal>,
-                <literal>LOG_ALERT</literal>,
-                <literal>LOG_CRIT</literal>,
-                <literal>LOG_ERR</literal>,
-                <literal>LOG_WARNING</literal>,
-                <literal>LOG_NOTICE</literal>,
-                <literal>LOG_INFO</literal>,
-                <literal>LOG_DEBUG</literal>, as defined in
+                <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><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>
                 for details. It is recommended to use this call to
                 <filename>syslog.h</filename>, see
                 <citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>
                 for details. It is recommended to use this call to
                 <para><function>sd_journal_printv()</function> is
                 similar to <function>sd_journal_print()</function> but
                 takes a variable argument list encapsulated in an
                 <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 <literal>va_list</literal> (see
+                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
                 <citerefentry><refentrytitle>stdarg</refentrytitle><manvolnum>3</manvolnum></citerefentry>
                 for more information) instead of the format string. It
-                is otherwise equivalent in behaviour.</para>
+                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,
 
                 <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 NULL. The strings passed should be of
+                terminated by <constant>NULL</constant>. The strings passed should be of
                 the format <literal>VARIABLE=value</literal>. The
                 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. 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
+                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
                 <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>
                 for details, but additional application defined fields
-                may be used.</para>
+                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
 
                 <para><function>sd_journal_sendv()</function> is
                 similar to <function>sd_journal_send()</function> but
-                takes an array of <literal>struct iovec</literal> (as
+                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
                 defined in <filename>uio.h</filename>, see
                 <citerefentry><refentrytitle>readv</refentrytitle><manvolnum>3</manvolnum></citerefentry>
                 for details) instead of the format string. Each
                 particularly useful to submit binary objects to the
                 journal where that is necessary.</para>
 
                 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><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
                 <para>Note that <function>sd_journal_send()</function>
                 is a wrapper around
                 <function>sd_journal_sendv()</function> to make it
@@ -165,20 +189,20 @@ sd_journal_send("MESSAGE=Hello World, this is PID %lu!", (unsigned long) getpid(
                 <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
                 <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
+                not desired, it can be turned off by defining
                 SD_JOURNAL_SUPPRESS_LOCATION before including
                 <filename>sd-journal.h</filename>.</para>
 
                 <para><citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>
                 SD_JOURNAL_SUPPRESS_LOCATION before including
                 <filename>sd-journal.h</filename>.</para>
 
                 <para><citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>
-                and and <function>sd_journal_print()</function> may
-                largely be used interchangably
+                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
                 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, file names, and
+                benefit of logging source code line, filenames, and
                 functions as meta data along all entries, and
                 guaranteeing chronological ordering with structured
                 log entries that are generated via
                 functions as meta data along all entries, and
                 guaranteeing chronological ordering with structured
                 log entries that are generated via
@@ -190,8 +214,10 @@ sd_journal_send("MESSAGE=Hello World, this is PID %lu!", (unsigned long) getpid(
         <refsect1>
                 <title>Return Value</title>
 
         <refsect1>
                 <title>Return Value</title>
 
-                <para>The four calls return 0 on success or a
-                negative errno-style error code.</para>
+                <para>The four calls return 0 on success or a negative
+                errno-style error code. The
+                <citerefentry><refentrytitle>errno</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+                variable itself is not altered.</para>
         </refsect1>
 
         <refsect1>
         </refsect1>
 
         <refsect1>
@@ -203,8 +229,7 @@ sd_journal_send("MESSAGE=Hello World, this is PID %lu!", (unsigned long) getpid(
                 <function>sd_journal_sendv()</function> interfaces
                 are available as shared library, which can be compiled
                 and linked to with the
                 <function>sd_journal_sendv()</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>
+                <constant>libsystemd-journal</constant> <citerefentry><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>
                 file.</para>
         </refsect1>
 
                 file.</para>
         </refsect1>
 
@@ -216,6 +241,8 @@ sd_journal_send("MESSAGE=Hello World, this is PID %lu!", (unsigned long) getpid(
                         <citerefentry><refentrytitle>sd-journal</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
                         <citerefentry><refentrytitle>sd_journal_stream_fd</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
                         <citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
                         <citerefentry><refentrytitle>sd-journal</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
                         <citerefentry><refentrytitle>sd_journal_stream_fd</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
                         <citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+                        <citerefentry><refentrytitle>perror</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+                        <citerefentry><refentrytitle>errno</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
                         <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>
                 </para>
         </refsect1>
                         <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>
                 </para>
         </refsect1>