SD_SEAT_GET_ACTIVE(3)						sd_seat_get_active					     SD_SEAT_GET_ACTIVE(3)

NAME

       sd_seat_get_active, sd_seat_get_sessions, sd_seat_can_multi_session - Determine state of a specific seat

SYNOPSIS

       #include <systemd/sd-login.h>

       int sd_seat_get_active(const char* seat, char** session, uid_t* uid);

       int sd_seat_get_sessions(const char* seat, char*** sessions, uid_t** uid, unsigned* n_uids);

       int sd_seat_can_multi_session(const char* seat);

DESCRIPTION

       sd_seat_get_active() may be used to determine which session is currently active on a seat, if there is any. Returns the session identifier
       and the user identifier of the Unix user the session is belonging to. Either the session or the user identifier parameter can be be passed
       NULL, in case only one of the parameters shall be queried. The returned string needs to be freed with the libc free(3) call after use.

       sd_seat_get_sessions() may be used to determine all sessions on the specified seat. Returns two arrays, one (NULL terminated) with the
       session identifiers of the sessions and one with the user identifiers of the Unix users the sessions belong to. An additional parameter may
       be used to return the number of entries in the latter array. The two arrays and the latter parameter may be passed as NULL in case these
       values need not to be determined. The arrays and the strings referenced by them need to be freed with the libc free(3) call after use. Note
       that instead of an empty array NULL may be returned and should be considered equivalent to an empty array.

       sd_seat_can_multi_session() may be used to determine whether a specific seat is capable of multi-session, i.e. allows multiple login
       sessions in parallel (whith only one being active at a time).

       If the seat parameter of any of these functions is passed as NULL the operation is executed for the seat of the session of the calling
       process, if there is any.

RETURN VALUE

       On success sd_seat_get_active() return return 0 or a positive integer. On success sd_seat_get_sessions() returns the number of entries in
       the session identifier array. If the test succeeds sd_seat_can_multi_session returns a positive integer, if it fails 0. On failure, these
       calls return a negative errno-style error code.

NOTES

       The sd_seat_get_active(), sd_seat_get_sessions(), and sd_seat_can_multi_session() interfaces are available as shared library, which can be
       compiled and linked to with the libsystemd-login pkg-config(1) file.

SEE ALSO

       systemd(1), sd-login(7), sd_session_get_seat(3)

AUTHOR

       Lennart Poettering <lennart@poettering.net>
	   Developer

systemd 							    10/07/2013						     SD_SEAT_GET_ACTIVE(3)