Index · Directives systemd 239


sd_bus_message_read_basic — Read a basic type from a message


#include <systemd/sd-bus.h>
int sd_bus_message_read_basic(sd_bus_message *m,
 char type,
 void *p);


sd_bus_message_read_basic() reads a basic type from a message and advances the read position in the message. The set of basic types and their ascii codes passed in type are described in the D-Bus Specification.

If p is not NULL, it should contain a pointer to an appropriate object. For example, if type is 'y', the object passed in p should have type uint8_t *. If type is 's', the object passed in p should have type const char **. Note that, if the basic type is a pointer (e.g., const char * in the case of a string), the pointer is only borrowed and the contents must be copied if they are to be used after the end of the messages lifetime. Similarly, during the lifetime of such a pointer, the message must not be modified.

If there is no object of the specified type at the current position in the message, an error is returned.

Return Value

On success, sd_bus_message_read_basic() returns 0 or a positive integer. On failure, it returns a negative errno-style error code.

See Also

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