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* session);
DESCRIPTIONsd_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).
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 ALSOsystemd(1), sd-login(7), sd_session_get_seat(3)AUTHOR
Lennart Poettering <lennart@poettering.net>
Developer
systemd 05/23/2012 SD_SEAT_GET_ACTIVE(3)