diff options
Diffstat (limited to 'man/sd_bus_error.xml')
| -rw-r--r-- | man/sd_bus_error.xml | 389 |
1 files changed, 0 insertions, 389 deletions
diff --git a/man/sd_bus_error.xml b/man/sd_bus_error.xml deleted file mode 100644 index c2d7ee389b..0000000000 --- a/man/sd_bus_error.xml +++ /dev/null @@ -1,389 +0,0 @@ -<?xml version='1.0'?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*--> -<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" -"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> - -<!-- - This file is part of systemd. - - Copyright 2014 Zbigniew Jędrzejewski-Szmek - - systemd is free software; you can redistribute it and/or modify it - under the terms of the GNU Lesser General Public License as published by - the Free Software Foundation; either version 2.1 of the License, or - (at your option) any later version. - - systemd is distributed in the hope that it will be useful, but - WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public License - along with systemd; If not, see <http://www.gnu.org/licenses/>. ---> - -<refentry id="sd_bus_error"> - - <refentryinfo> - <title>sd_bus_error</title> - <productname>systemd</productname> - - <authorgroup> - <author> - <contrib>A monkey with a typewriter</contrib> - <firstname>Zbigniew</firstname> - <surname>Jędrzejewski-Szmek</surname> - <email>zbyszek@in.waw.pl</email> - </author> - </authorgroup> - </refentryinfo> - - <refmeta> - <refentrytitle>sd_bus_error</refentrytitle> - <manvolnum>3</manvolnum> - </refmeta> - - <refnamediv> - <refname>sd_bus_error</refname> - <refname>SD_BUS_ERROR_MAKE_CONST</refname> - <refname>SD_BUS_ERROR_NULL</refname> - <refname>sd_bus_error_free</refname> - <refname>sd_bus_error_set</refname> - <refname>sd_bus_error_setf</refname> - <refname>sd_bus_error_set_const</refname> - <refname>sd_bus_error_set_errno</refname> - <refname>sd_bus_error_set_errnof</refname> - <refname>sd_bus_error_set_errnofv</refname> - <refname>sd_bus_error_get_errno</refname> - <refname>sd_bus_error_copy</refname> - <refname>sd_bus_error_is_set</refname> - <refname>sd_bus_error_has_name</refname> - - <refpurpose>sd-bus error handling</refpurpose> - </refnamediv> - - <refsynopsisdiv> - <funcsynopsis> - <funcsynopsisinfo>#include <systemd/sd-bus.h></funcsynopsisinfo> - - <funcsynopsisinfo>typedef struct { - const char *name; - const char *message; - ... -} sd_bus_error;</funcsynopsisinfo> - - <para> - <constant>SD_BUS_ERROR_MAKE_CONST(<replaceable>name</replaceable>, <replaceable>message</replaceable>)</constant> - </para> - <para> - <constant>SD_BUS_ERROR_NULL</constant> - </para> - - <funcprototype> - <funcdef>void <function>sd_bus_error_free</function></funcdef> - <paramdef>sd_bus_error *<parameter>e</parameter></paramdef> - </funcprototype> - - <funcprototype> - <funcdef>int <function>sd_bus_error_set</function></funcdef> - <paramdef>sd_bus_error *<parameter>e</parameter></paramdef> - <paramdef>const char *<parameter>name</parameter></paramdef> - <paramdef>const char *<parameter>message</parameter></paramdef> - </funcprototype> - - <funcprototype> - <funcdef>int <function>sd_bus_error_setf</function></funcdef> - <paramdef>sd_bus_error *<parameter>e</parameter></paramdef> - <paramdef>const char *<parameter>name</parameter></paramdef> - <paramdef>const char *<parameter>format</parameter></paramdef> - <paramdef>...</paramdef> - </funcprototype> - - <funcprototype> - <funcdef>int <function>sd_bus_error_set_const</function></funcdef> - <paramdef>sd_bus_error *<parameter>e</parameter></paramdef> - <paramdef>const char *<parameter>name</parameter></paramdef> - <paramdef>const char *<parameter>message</parameter></paramdef> - </funcprototype> - - <funcprototype> - <funcdef>int <function>sd_bus_error_set_errno</function></funcdef> - <paramdef>sd_bus_error *<parameter>e</parameter></paramdef> - <paramdef>int <parameter>error</parameter></paramdef> - </funcprototype> - - <funcprototype> - <funcdef>int <function>sd_bus_error_set_errnof</function></funcdef> - <paramdef>sd_bus_error *<parameter>e</parameter></paramdef> - <paramdef>int <parameter>error</parameter></paramdef> - <paramdef>const char *<parameter>format</parameter></paramdef> - <paramdef>...</paramdef> - </funcprototype> - - <funcprototype> - <funcdef>int <function>sd_bus_error_set_errnofv</function></funcdef> - <paramdef>sd_bus_error *<parameter>e</parameter></paramdef> - <paramdef>int <parameter>error</parameter></paramdef> - <paramdef>const char *<parameter>format</parameter></paramdef> - <paramdef>va_list ap</paramdef> - </funcprototype> - - <funcprototype> - <funcdef>int <function>sd_bus_error_get_errno</function></funcdef> - <paramdef>const sd_bus_error *<parameter>e</parameter></paramdef> - </funcprototype> - - <funcprototype> - <funcdef>int <function>sd_bus_error_copy</function></funcdef> - <paramdef>sd_bus_error *<parameter>dst</parameter></paramdef> - <paramdef>const sd_bus_error *<parameter>e</parameter></paramdef> - </funcprototype> - - <funcprototype> - <funcdef>int <function>sd_bus_error_is_set</function></funcdef> - <paramdef>const sd_bus_error *<parameter>e</parameter></paramdef> - </funcprototype> - - <funcprototype> - <funcdef>int <function>sd_bus_error_has_name</function></funcdef> - <paramdef>const sd_bus_error *<parameter>e</parameter></paramdef> - <paramdef>const char *<parameter>name</parameter></paramdef> - </funcprototype> - </funcsynopsis> - - </refsynopsisdiv> - - <refsect1> - <title>Description</title> - - <para>The <structname>sd_bus_error</structname> structure carries - information about a D-Bus error condition. The functions described - below may be used to set and query fields in this structure. The - <structfield>name</structfield> field contains a short identifier - of an error. It should follow the rules for error names described - in the D-Bus specification, subsection <ulink - url="http://dbus.freedesktop.org/doc/dbus-specification.html#message-protocol-names">Valid - Names</ulink>. A number of common, standardized error names are - described in - <citerefentry><refentrytitle>sd-bus-errors</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - but additional domain-specific errors may be defined by - applications. The <structfield>message</structfield> field usually - contains a human-readable string describing the details, but might - be NULL. An unset <structname>sd_bus_error</structname> structure - should have both fields initialized to NULL. Set an error - structure to <constant>SD_BUS_ERROR_NULL</constant> in order to - reset both fields to NULL. When no longer necessary, resources - held by the <structname>sd_bus_error</structname>structure should - be destroyed with <function>sd_bus_error_free()</function>.</para> - - <para><function>sd_bus_error_set()</function> sets an error - structure to the specified name and message strings. The strings - will be copied into internal, newly allocated memory. It is - essential to free the error structure again when it is not - required anymore (see above). The function will return an - <varname>errno</varname>-like negative value (see <citerefentry - project='man-pages'><refentrytitle>errno</refentrytitle><manvolnum>3</manvolnum></citerefentry>) - determined from the specified error name. Various well-known - D-Bus errors are converted to well-known <varname>errno</varname> - counterparts, and the other ones to <constant>-EIO</constant>. See - <citerefentry><refentrytitle>sd-bus-errors</refentrytitle><manvolnum>3</manvolnum></citerefentry> - for a list of well-known error names. Additional error mappings - may be defined with - <citerefentry><refentrytitle>sd_bus_error_add_map</refentrytitle><manvolnum>3</manvolnum></citerefentry>. If - <parameter>e</parameter> is NULL, no error structure is initialized, - but the error is still converted into an - <varname>errno</varname>-style error. If - <parameter>name</parameter> is <constant>NULL</constant>, it is - assumed that no error occurred, and 0 is returned. This means that - this function may be conveniently used in a - <function>return</function> statement. If - <parameter>message</parameter> is NULL, no message is set. This - call can fail if no memory may be allocated for the name and - message strings, in which case an - <constant>SD_BUS_ERROR_NO_MEMORY</constant> error might be set - instead and -ENOMEM be returned. Do not use this call on error - structures that are already initialized. If you intend to reuse an - error structure, free the old data stored in it with - <function>sd_bus_error_free()</function> first.</para> - - <para><function>sd_bus_error_setf()</function> is similar to - <function>sd_bus_error_set()</function>, but takes a <citerefentry - project='man-pages'><refentrytitle>printf</refentrytitle><manvolnum>3</manvolnum></citerefentry> - format string and corresponding arguments to generate the - <structfield>message</structfield> field.</para> - - <para><function>sd_bus_error_set_const()</function> is similar to - <function>sd_bus_error_set()</function>, but the string parameters - are not copied internally, and must hence remain constant and - valid for the lifetime of <parameter>e</parameter>. Use this call - to avoid memory allocations when setting error structures. Since - this call does not allocate memory, it will not fail with an - out-of-memory condition as - <function>sd_bus_error_set()</function> can, as described - above. Alternatively, the - <constant>SD_BUS_ERROR_MAKE_CONST()</constant> macro may be used - to generate a literal, constant bus error structure - on-the-fly.</para> - - <para><function>sd_bus_error_set_errno()</function> will set - <structfield>name</structfield> from an - <varname>errno</varname>-like value that is converted to a D-Bus - error. <citerefentry - project='die-net'><refentrytitle>strerror_r</refentrytitle><manvolnum>3</manvolnum></citerefentry> - will be used to set <structfield>message</structfield>. Well-known - D-Bus error names will be used for <structfield>name</structfield> - if applicable, otherwise a name in the - <literal>System.Error.</literal> namespace will be generated. The - sign of the specified error number is ignored. The absolute value - is used implicitly. The call always returns a negative value, for - convenient usage in <function>return</function> statements. This - call might fail due to lack of memory, in which case an - <constant>SD_BUS_ERROR_NO_MEMORY</constant> error is set instead, - and -ENOMEM is returned.</para> - - <para><function>sd_bus_error_set_errnof()</function> is similar to - <function>sd_bus_error_set_errno()</function>, but in addition to - <parameter>error</parameter>, takes a <citerefentry - project='man-pages'><refentrytitle>printf</refentrytitle><manvolnum>3</manvolnum></citerefentry> - format string and corresponding arguments. The - <structfield>message</structfield> field will be generated from - <parameter>format</parameter> and the arguments.</para> - - <para><function>sd_bus_error_set_errnofv()</function> is similar to - <function>sd_bus_error_set_errnof()</function>, but takes the - format string parameters as <citerefentry - project='man-pages'><refentrytitle>va_arg</refentrytitle><manvolnum>3</manvolnum></citerefentry> - parameter list.</para> - - <para><function>sd_bus_error_get_errno()</function> converts the - <structfield>name</structfield> field of an error structure to an - <varname>errno</varname>-like (positive) value using the same - rules as <function>sd_bus_error_set()</function>. If - <parameter>e</parameter> is <constant>NULL</constant>, 0 will be - returned.</para> - - <para><function>sd_bus_error_copy()</function> will initialize - <parameter>dst</parameter> using the values in - <parameter>e</parameter>. If the strings in - <parameter>e</parameter> were set using - <function>sd_bus_set_error_const()</function>, they will be shared. - Otherwise, they will be copied. Returns a converted - <varname>errno</varname>-like, negative error code.</para> - - <para><function>sd_bus_error_is_set()</function> will return a - non-zero value if <parameter>e</parameter> is - non-<constant>NULL</constant> and an error has been set, - <constant>false</constant> otherwise.</para> - - <para><function>sd_bus_error_has_name()</function> will return a - non-zero value if <parameter>e</parameter> is - non-<constant>NULL</constant> and an error with the same - <parameter>name</parameter> has been set, - <constant>false</constant> otherwise.</para> - - <para><function>sd_bus_error_free()</function> will destroy - resources held by <parameter>e</parameter>. The parameter itself - will not be deallocated, and must be <citerefentry - project='man-pages'><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry>d - by the caller if necessary. The function may also be called safely - on unset errors (error structures with both fields set to NULL), - in which case it performs no operation. This call will reset the - error structure after freeing the data, so that all fields are set - to NULL. The structure may be reused afterwards.</para> - </refsect1> - - <refsect1> - <title>Return Value</title> - - <para>The functions <function>sd_bus_error_set()</function>, - <function>sd_bus_error_setf()</function>, and - <function>sd_bus_error_set_const()</function>, when successful, - return the negative errno value corresponding to the - <parameter>name</parameter> parameter. The functions - <function>sd_bus_error_set_errno()</function>, - <function>sd_bus_error_set_errnof()</function> and - <function>sd_bus_error_set_errnofv()</function>, when successful, - return the negative value of the <parameter>error</parameter> - parameter. If an error occurs, one of the negative error values - listed below will be returned.</para> - - <para><function>sd_bus_error_get_errno()</function> returns - <constant>false</constant> when <parameter>e</parameter> is - <constant>NULL</constant>, and a positive errno value mapped from - <parameter>e->name</parameter> otherwise.</para> - - <para><function>sd_bus_error_copy()</function> returns 0 or a - positive integer on success, and a negative error value converted - from the error name otherwise.</para> - - <para><function>sd_bus_error_is_set()</function> returns a - non-zero value when <parameter>e</parameter> and the - <structfield>name</structfield> field are - non-<constant>NULL</constant>, zero otherwise.</para> - - <para><function>sd_bus_error_has_name()</function> returns a - non-zero value when <parameter>e</parameter> is - non-<constant>NULL</constant> and the - <structfield>name</structfield> field is equal to - <parameter>name</parameter>, zero otherwise.</para> - </refsect1> - - <refsect1> - <title>Reference ownership</title> - <para><structname>sd_bus_error</structname> is not reference - counted. Users should destroy resources held by it by calling - <function>sd_bus_error_free()</function>. Usually, error structures - are allocated on the stack or passed in as function parameters, - but they may also be allocated dynamically, in which case it is - the duty of the caller to <citerefentry - project='man-pages'><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry> - the memory held by the structure itself after freeing its contents - with <function>sd_bus_error_free()</function>.</para> - </refsect1> - - <refsect1> - <title>Errors</title> - - <para>Returned errors may indicate the following problems:</para> - - <variablelist> - - <varlistentry> - <term><constant>-EINVAL</constant></term> - - <listitem><para>Error was already set in - <structname>sd_bus_error</structname> structure when one the - error-setting functions was called.</para></listitem> - </varlistentry> - - <varlistentry> - <term><constant>-ENOMEM</constant></term> - - <listitem><para>Memory allocation failed.</para></listitem> - </varlistentry> - </variablelist> - </refsect1> - - <refsect1> - <title>Notes</title> - - <para><function>sd_bus_set_error()</function> and other functions - described here 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-bus</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd-bus-errors</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd_bus_error_add_map</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry project='man-pages'><refentrytitle>errno</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry project='die-net'><refentrytitle>strerror_r</refentrytitle><manvolnum>3</manvolnum></citerefentry> - </para> - </refsect1> - -</refentry> |