Man page - sd_bus_message_has_signature(3)

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Manual

SD_BUS_MESSAGE_GET_SIGNATURE

NAME
SYNOPSIS
DESCRIPTION
RETURN VALUE
Errors
NOTES
HISTORY
SEE ALSO

NAME

sd_bus_message_get_signature, sd_bus_message_is_empty, sd_bus_message_has_signature - Query bus message signature

SYNOPSIS

#include <systemd/sd-bus.h>

const char* sd_bus_message_get_signature(sd_bus_message * message , int complete );

int sd_bus_message_is_empty(sd_bus_message * message );

int sd_bus_message_has_signature(sd_bus_message * message , const char * signature );

DESCRIPTION

sd_bus_message_get_signature() returns the signature of message message . If complete is true, the signature of the whole message is returned, and just the signature of the currently open container otherwise.

sd_bus_message_is_empty() returns true if the message is empty, i.e. when its signature is empty.

sd_bus_message_has_signature() returns true if the signature of the message message matches given signature . Parameter signature may be NULL , this is treated the same as an empty string, which is equivalent to calling sd_bus_message_is_empty() .

RETURN VALUE

On success, sd_bus_message_get_signature() returns the signature, and NULL on error.

The other functions return 0 or a positive integer on success. On failure, they return a negative errno-style error code.

Errors

Returned errors may indicate the following problems:

-EINVAL

The message parameter is NULL .

NULL

The message parameter is NULL .

NOTES

Functions described here are available as a shared library, which can be compiled against and linked to with the libsystemd 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_signature() , sd_bus_message_is_empty() , and sd_bus_message_has_signature() were added in version 240.

SEE ALSO

systemd (1), sd-bus (3), sd_bus_message_new (3)