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Diffstat (limited to 'man/sd_bus_error.xml')
| -rw-r--r-- | man/sd_bus_error.xml | 344 |
1 files changed, 159 insertions, 185 deletions
diff --git a/man/sd_bus_error.xml b/man/sd_bus_error.xml index b8cb339cec..6dc4541eb1 100644 --- a/man/sd_bus_error.xml +++ b/man/sd_bus_error.xml @@ -44,11 +44,15 @@ <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> @@ -75,7 +79,7 @@ </para> <funcprototype> - <funcdef>int <function>sd_bus_error_free</function></funcdef> + <funcdef>void <function>sd_bus_error_free</function></funcdef> <paramdef>sd_bus_error *<parameter>e</parameter></paramdef> </funcprototype> @@ -116,6 +120,14 @@ </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> @@ -138,234 +150,194 @@ </funcprototype> </funcsynopsis> - <para> - <constant>SD_BUS_ERROR_FAILED</constant> - </para> - <para> - <constant>SD_BUS_ERROR_NO_MEMORY</constant> - </para> - <para> - <constant>SD_BUS_ERROR_SERVICE_UNKNOWN</constant> - </para> - <para> - <constant>SD_BUS_ERROR_NAME_HAS_NO_OWNER</constant> - </para> - <para> - <constant>SD_BUS_ERROR_NO_REPLY</constant> - </para> - <para> - <constant>SD_BUS_ERROR_IO_ERROR</constant> - </para> - <para> - <constant>SD_BUS_ERROR_BAD_ADDRESS</constant> - </para> - <para> - <constant>SD_BUS_ERROR_NOT_SUPPORTED</constant> - </para> - <para> - <constant>SD_BUS_ERROR_LIMITS_EXCEEDED</constant> - </para> - <para> - <constant>SD_BUS_ERROR_ACCESS_DENIED</constant> - </para> - <para> - <constant>SD_BUS_ERROR_AUTH_FAILED</constant> - </para> - <para> - <constant>SD_BUS_ERROR_NO_SERVER</constant> - </para> - <para> - <constant>SD_BUS_ERROR_TIMEOUT</constant> - </para> - <para> - <constant>SD_BUS_ERROR_NO_NETWORK</constant> - </para> - <para> - <constant>SD_BUS_ERROR_ADDRESS_IN_USE</constant> - </para> - <para> - <constant>SD_BUS_ERROR_DISCONNECTED</constant> - </para> - <para> - <constant>SD_BUS_ERROR_INVALID_ARGS</constant> - </para> - <para> - <constant>SD_BUS_ERROR_FILE_NOT_FOUND</constant> - </para> - <para> - <constant>SD_BUS_ERROR_FILE_EXISTS</constant> - </para> - <para> - <constant>SD_BUS_ERROR_UNKNOWN_METHOD</constant> - </para> - <para> - <constant>SD_BUS_ERROR_UNKNOWN_OBJECT</constant> - </para> - <para> - <constant>SD_BUS_ERROR_UNKNOWN_INTERFACE</constant> - </para> - <para> - <constant>SD_BUS_ERROR_UNKNOWN_PROPERTY</constant> - </para> - <para> - <constant>SD_BUS_ERROR_PROPERTY_READ_ONLY</constant> - </para> - <para> - <constant>SD_BUS_ERROR_UNIX_PROCESS_ID_UNKNOWN</constant> - </para> - <para> - <constant>SD_BUS_ERROR_INVALID_SIGNATURE</constant> - </para> - <para> - <constant>SD_BUS_ERROR_INCONSISTENT_MESSAGE</constant> - </para> - <para> - <constant>SD_BUS_ERROR_MATCH_RULE_NOT_FOUND</constant> - </para> - <para> - <constant>SD_BUS_ERROR_MATCH_RULE_INVALID</constant> - </para> - </refsynopsisdiv> <refsect1> <title>Description</title> <para>The <structname>sd_bus_error</structname> structure carries - information for a <filename>sd-bus</filename> error. The - functions described below can 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 + 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>. The <structfield>message</structfield> is a human - readable string describing the details. When no longer necessary, - resources held by this structure should be destroyed with - <function>sd_bus_error_free</function>.</para> - - <para><function>sd_bus_error_set</function> will return an - errno-like negative value returned based on parameter - <parameter>name</parameter> (see - <citerefentry project='man-pages'><refentrytitle>errno</refentrytitle><manvolnum>3</manvolnum></citerefentry>). - Various well-known D-Bus errors are converted to specific values, - and the remaining ones to <constant>-ENXIO</constant>. Well-known - D-Bus error names are available as constants - <constant>SD_BUS_ERROR_FAILED</constant>, etc., listed above. If + 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.</para> - - <para>If <parameter>e</parameter> is not - <constant>NULL</constant>, <structfield>name</structfield> and - <structfield>message</structfield> in the - <structname>sd_bus_error</structname> structure - <parameter>e</parameter> points at will be filled in. As described above, - <parameter>name</parameter> may be <constant>NULL</constant>, - which is treated as no error. Parameter - <parameter>message</parameter> may also be - <constant>NULL</constant>, in which case no message is specified. - <function>sd_bus_error_set</function> will make internal copies of - specified strings.</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 - <structname>message</structname>.</para> - - <para><function>sd_bus_error_set_const</function> is similar to - <function>sd_bus_error_set</function>, but string parameters are - not copied internally, and must remain valid for the lifetime of - <parameter>e</parameter>.</para> - - <para><function>sd_bus_error_set_errno</function> will set - <structfield>name</structfield> based on an errno-like value. - <citerefentry project='die-net'><refentrytitle>strerror</refentrytitle><manvolnum>3</manvolnum></citerefentry> + <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 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 available, otherwise a name in the - <literal>System.Error</literal> namespace will be generated. - </para> - - <para><function>sd_bus_error_set_errnof</function> is similar to - <function>sd_bus_error_set_errno</function>, but in addition to - <parameter>name</parameter>, takes a - <citerefentry project='man-pages'><refentrytitle>printf</refentrytitle><manvolnum>3</manvolnum></citerefentry> - format and corresponding arguments. - <structfield>name</structfield> will be generated from + 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 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_get_errno</function> will convert - <structname>e->name</structname> to an errno-like value using the - same rules as <function>sd_bus_error_set</function>. If + <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 + <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.</para> + <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 - <constant>true</constant> if <parameter>e</parameter> is + <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 true - if <parameter>e</parameter> is non-<constant>NULL</constant> and - an error with the same <parameter>name</parameter> has been set, + <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.</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>Functions <function>sd_bus_error_set</function>, - <function>sd_bus_error_setf</function>, - <function>sd_bus_error_set_const</function>, when successful, + <para>The functions <function>sd_bus_error_set()</function>, + <function>sd_bus_error_setf()</function>, + <function>sd_bus_error_set_const()</function>, when successful, return the negative errno value corresponding to the <parameter>name</parameter> parameter. Functions - <function>sd_bus_error_set_errno</function> and - <function>sd_bus_error_set_errnof</function>, when successful, - return the value of the <parameter>errno</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 + <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 one of the negative error values - listed below 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 - <constant>true</constant> when <parameter>e</parameter> and - <parameter>e->name</parameter> are non-<constant>NULL</constant>, - <constant>false</constant> 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 - <constant>true</constant> when <parameter>e</parameter> is - non-<constant>NULL</constant> and <parameter>e->name</parameter> - is equal to <parameter>name</parameter>, - <constant>false</constant> 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>.</para> + <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> @@ -407,8 +379,10 @@ <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</refentrytitle><manvolnum>3</manvolnum></citerefentry> + <citerefentry project='die-net'><refentrytitle>strerror_r</refentrytitle><manvolnum>3</manvolnum></citerefentry> </para> </refsect1> |