Man page - sd_bus_message_is_method_error(3)

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Manual

SD_BUS_MESSAGE_GET_TYPE

NAME
SYNOPSIS
DESCRIPTION
RETURN VALUE
Errors
NOTES
HISTORY
SEE ALSO

NAME

sd_bus_message_get_type, sd_bus_message_get_error, sd_bus_message_get_errno, sd_bus_message_get_creds, sd_bus_message_is_signal, sd_bus_message_is_method_call, sd_bus_message_is_method_error - Query bus message addressing/credentials metadata

SYNOPSIS

#include <systemd/sd-bus.h>

int sd_bus_message_get_type(sd_bus_messageĀ * m , uint8_tĀ * type );

sd_bus_error* sd_bus_message_get_error(sd_bus_messageĀ * m );

int sd_bus_message_get_errno(sd_bus_messageĀ * m );

sd_bus_creds* sd_bus_message_get_creds(sd_bus_messageĀ * m );

int sd_bus_message_is_signal(sd_bus_messageĀ * m , constĀ charĀ * interface , constĀ charĀ * member );

int sd_bus_message_is_method_call(sd_bus_messageĀ * m , constĀ charĀ * interface , constĀ charĀ * member );

int sd_bus_message_is_method_error(sd_bus_messageĀ * m , constĀ charĀ * name );

DESCRIPTION

sd_bus_message_get_type() returns the type of a message in the output parameter type , one of SD_BUS_MESSAGE_METHOD_CALL , SD_BUS_MESSAGE_METHOD_RETURN , SD_BUS_MESSAGE_METHOD_ERROR , SD_BUS_MESSAGE_SIGNAL . This type is either specified as a parameter when the message is created using sd_bus_message_new (3), or is set automatically when the message is created using sd_bus_message_new_signal (3), sd_bus_message_new_method_call (3), sd_bus_message_new_method_error (3) and similar functions.

sd_bus_message_get_error() returns the error stored in the message m , if there is any. Otherwise, it returns NULL . sd_bus_message_get_errno() returns the error stored in the message m as a positive errno-style value, if there is any. Otherwise, it returns zero. Errors are mapped to errno values according to the default and any additional registered error mappings. See sd-bus-errors (3) and sd_bus_error_add_map (3).

sd_bus_message_get_creds() returns the message credentials attached to the message m . If no credentials are attached to the message, it returns NULL . Ownership of the credentials instance is not transferred to the caller and hence should not be freed.

sd_bus_message_is_signal() checks if message m is a signal message. If interface is non-null, it also checks if the message has the same interface set. If member is non-null, it also checks if the message has the same member set. Also see sd_bus_message_new_signal (3). It returns true when all checks pass.

sd_bus_message_is_method_call() checks if message m is a method call message. If interface is non-null, it also checks if the message has the same interface set. If member is non-null, it also checks if the message has the same member set. Also see sd_bus_message_new_method_call (3). It returns true when all checks pass.

sd_bus_message_is_method_error() checks if message m is an error reply message. If name is non-null, it also checks if the message has the same error identifier set. Also see sd_bus_message_new_method_error (3). It returns true when all checks pass.

RETURN VALUE

On success, these functions (except sd_bus_message_get_error() and sd_bus_message_get_creds() ) return a non-negative integer. On failure, they return a negative errno-style error code. sd_bus_message_get_errno() always returns a non-negative integer, even on failure.

Errors

Returned errors may indicate the following problems:

-EINVAL

The message parameter m or an output parameter is NULL .

NOTES

Functions described here are available as a shared library, which can be compiled against and linked to with the libsystemdĀ pkg-config (1) file.

The code described here uses getenv (3), which is declared to be not multi-thread-safe. This means that the code calling the functions described here must not call setenv (3) from a parallel thread. It is recommended to only do calls to setenv() from an early phase of the program when no other threads have been started.

HISTORY

sd_bus_message_get_type() , sd_bus_message_is_signal() , sd_bus_message_is_method_call() , and sd_bus_message_is_method_error() were added in version 240.

sd_bus_message_get_error() , sd_bus_message_get_errno() , and sd_bus_message_get_creds() were added in version 246.

SEE ALSO

systemd (1), sd-bus (3), sd_bus_message_new (3), sd_bus_message_set_destination (3), sd-bus-errors (3), sd_bus_error_add_map (3)