int sd_bus_message_rewind(sd_bus_message *m, int complete);
sd_bus_message_rewind() moves the "read pointer" in the message m to either the beginning of the message (if complete is true) or to the beginning of the currently open container. If no container is open, complete has no effect.
On success, this function returns 0 or a positive integer. The value is zero if the current container or whole message in case no container is open is empty, and positive otherwise. On failure, it returns a negative errno-style error code.
Returned errors may indicate the following problems:
The m parameter is NULL.
The message m has not been sealed.
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.
systemd(1), sd-bus(3), sd_bus_message_read(3)
sd-bus(3), sd_bus_message_dump(3), systemd.directives(7), systemd.index(7).