1SD-LOGIN(3)                        sd-login                        SD-LOGIN(3)
2
3
4

NAME

6       sd-login - APIs for tracking logins
7

SYNOPSIS

9       #include <systemd/sd-login.h>
10
11       pkg-config --cflags --libs libsystemd
12

DESCRIPTION

14       sd-login.h provides APIs to introspect and monitor seat, login session
15       and user status information on the local system.
16
17       See Multi-Seat on Linux[1] for an introduction into multi-seat support
18       on Linux, the background for this set of APIs.
19
20       Note that these APIs only allow purely passive access and monitoring of
21       seats, sessions and users. To actively make changes to the seat
22       configuration, terminate login sessions, or switch session on a seat
23       you need to utilize the D-Bus API of systemd-logind, instead.
24
25       These functions synchronously access data in /proc, /sys/fs/cgroup and
26       /run. All of these are virtual file systems, hence the runtime cost of
27       the accesses is relatively cheap.
28
29       It is possible (and often a very good choice) to mix calls to the
30       synchronous interface of sd-login.h with the asynchronous D-Bus
31       interface of systemd-logind. However, if this is done you need to think
32       a bit about possible races since the stream of events from D-Bus and
33       from sd-login.h interfaces such as the login monitor are asynchronous
34       and not ordered against each other.
35
36       If the functions return string arrays, these are generally NULL
37       terminated and need to be freed by the caller with the libc free(3)
38       call after use, including the strings referenced therein. Similarly,
39       individual strings returned need to be freed, as well.
40
41       As a special exception, instead of an empty string array NULL may be
42       returned, which should be treated equivalent to an empty string array.
43
44       See sd_pid_get_session(3), sd_uid_get_state(3),
45       sd_session_is_active(3), sd_seat_get_active(3), sd_get_seats(3),
46       sd_login_monitor_new(3) for more information about the functions
47       implemented.
48

NOTES

50       These APIs are implemented as a shared library, which can be compiled
51       and linked to with the libsystemd pkg-config(1) file.
52

SEE ALSO

54       systemd(1), sd_pid_get_session(3), sd_uid_get_state(3),
55       sd_session_is_active(3), sd_seat_get_active(3), sd_get_seats(3),
56       sd_login_monitor_new(3), sd-daemon(3), sd-readahead(3), pkg-config(1)
57

NOTES

59        1. Multi-Seat on Linux
60           http://www.freedesktop.org/wiki/Software/systemd/multiseat
61
62
63
64systemd 219                                                        SD-LOGIN(3)
Impressum