sd_bus_message_new_method_error - Man Page

#include <systemd/sd-bus​.h>

int sd_bus_message_new_method_error(sd_bus_message *call, sd_bus_message **m, const sd_bus_error *e);

int sd_bus_message_new_method_errorf(sd_bus_message *call, sd_bus_message **m, const char *name, const char *format, ​...);

int sd_bus_message_new_method_errno(sd_bus_message *call, sd_bus_message **m, int error, const sd_bus_error *p);

int sd_bus_message_new_method_errnof(sd_bus_message *call, sd_bus_message **m, int error, const char *format, ​...);

The sd_bus_message_new_method_error() function creates a new bus message object that is an error reply to the call message, and returns it in the m output parameter​. The error information from error e is appended: the name field of e is used as the error identifier in the reply header (for example an error name such as "org​.freedesktop​.DBus​.Error​.NotSupported" or the equivalent symbolic SD_BUS_ERROR_NOT_SUPPORTED), and the message field is set as the human-readable error message string if present​. The error e must have the name field set, see sd_bus_error_is_set(3)​.

The sd_bus_message_new_method_errorf() function creates an error reply similarly to sd_bus_message_new_method_error(), but instead of a ready error structure, it takes an error identifier string name, plus a printf(3) format string format and corresponding arguments​. An error reply is sent with the error identifier name and the formatted string as the message​. name and format must not be NULL​.

The sd_bus_message_new_method_errno() function creates an error reply similarly to sd_bus_message_new_method_error(), but in addition to the error structure p, it takes an errno(3) error value in parameter error​. If the error p is set (see sd_bus_error_is_set(3)), it is used in the reply​. Otherwise, error is translated to an error identifier and used to create a new error structure using sd_bus_error_set_errno(3) and that is used in the reply​. (If error is zero, no error is actually set, and an error reply with no information is created​.)

The sd_bus_message_new_method_errnof() function creates an error reply similarly to sd_bus_message_new_method_error()​. It takes an errno(3) error value in parameter error, plus a printf(3) format string format and corresponding arguments​. "%m" may be used in the format string to refer to the error string corresponding to the specified errno code​. The error message is initialized using the error identifier generated from error and the formatted string​. (If error is zero, no error is actually set, and an error reply with no information is created​.)

These functions return 0 if the error reply was successfully created, and a negative errno-style error code otherwise​.

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

All functions listed here are thread-agnostic and only a single thread may operate on a given object at any given time​. Different threads may access the same object at different times​. Multiple independent objects may be used from different threads in parallel​.

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​.

systemd(1), sd-bus(3)