sd_seat_can_multi_session(3)

1SD_SEAT_GET_ACTIVE(3)         sd_seat_get_active         SD_SEAT_GET_ACTIVE(3)
2
3
4

NAME

6       sd_seat_get_active, sd_seat_get_sessions, sd_seat_can_multi_session,
7       sd_seat_can_tty, sd_seat_can_graphical - Determine state of a specific
8       seat
9

SYNOPSIS

11       #include <systemd/sd-login.h>
12
13       int sd_seat_get_active(const char *seat, char **session, uid_t *uid);
14
15       int sd_seat_get_sessions(const char *seat, char ***sessions,
16                                uid_t **uid, unsigned int *n_uids);
17
18       int sd_seat_can_multi_session(const char *seat);
19
20       int sd_seat_can_tty(const char *seat);
21
22       int sd_seat_can_graphical(const char *seat);
23

DESCRIPTION

25       sd_seat_get_active() may be used to determine which session is
26       currently active on a seat, if there is any. Returns the session
27       identifier and the user identifier of the Unix user the session is
28       belonging to. Either the session or the user identifier parameter can
29       be passed NULL, in case only one of the parameters shall be queried.
30       The returned string needs to be freed with the libc free(3) call after
31       use.
32
33       sd_seat_get_sessions() may be used to determine all sessions on the
34       specified seat. Returns two arrays, one (NULL terminated) with the
35       session identifiers of the sessions and one with the user identifiers
36       of the Unix users the sessions belong to. An additional parameter may
37       be used to return the number of entries in the latter array. The two
38       arrays and the latter parameter may be passed as NULL in case these
39       values need not to be determined. The arrays and the strings referenced
40       by them need to be freed with the libc free(3) call after use. Note
41       that instead of an empty array NULL may be returned and should be
42       considered equivalent to an empty array.
43
44       sd_seat_can_multi_session() may be used to determine whether a specific
45       seat is capable of multi-session, i.e. allows multiple login sessions
46       in parallel (with only one being active at a time).
47
48       sd_seat_can_tty() may be used to determine whether a specific seat
49       provides TTY functionality, i.e. is useful as a text console.
50
51       sd_seat_can_graphical() may be used to determine whether a specific
52       seat provides graphics functionality, i.e. is useful as a graphics
53       display.
54
55       If the seat parameter of any of these functions is passed as NULL, the
56       operation is executed for the seat of the session of the calling
57       process, if there is any.
58

RETURN VALUE

60       On success, sd_seat_get_active() returns 0 or a positive integer. On
61       success, sd_seat_get_sessions() returns the number of entries in the
62       session identifier array. If the test succeeds,
63       sd_seat_can_multi_session, sd_seat_can_tty and sd_seat_can_graphical
64       return a positive integer, if it fails 0. On failure, these calls
65       return a negative errno-style error code.
66

NOTES

68       The sd_seat_get_active(), sd_seat_get_sessions(),
69       sd_seat_can_multi_session(), sd_seat_can_tty() and
70       sd_seat_can_grapical() interfaces are available as a shared library,
71       which can be compiled and linked to with the libsystemd pkg-config(1)
72       file.
73

NAME

SYNOPSIS

DESCRIPTION

RETURN VALUE

NOTES

SEE ALSO