Provided by: libsystemd-dev_229-4ubuntu21.31_amd64 

NAME
sd_get_seats, sd_get_sessions, sd_get_uids, sd_get_machine_names - Determine available seats, sessions,
logged in users and virtual machines/containers
SYNOPSIS
#include <systemd/sd-login.h>
int sd_get_seats(char ***seats);
int sd_get_sessions(char ***sessions);
int sd_get_uids(uid_t **users);
int sd_get_machine_names(char ***machines);
DESCRIPTION
sd_get_seats() may be used to determine all currently available local seats. Returns a NULL terminated
array of seat identifiers. The returned array and all strings it references 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.
Similarly, sd_get_sessions() may be used to determine all current login sessions.
Similarly, sd_get_uids() may be used to determine all Unix users who currently have login sessions.
Similarly, sd_get_machine_names() may be used to determine all current virtual machines and containers on
the system.
Note that the returned lists are not sorted and in an undefined order.
RETURN VALUE
On success, sd_get_seats(), sd_get_sessions(), sd_get_uids() and sd_get_machine_names() return the number
of entries in the arrays. On failure, these calls return a negative errno-style error code.
ERRORS
Returned errors may indicate the following problems:
-EINVAL
An input parameter was invalid (out of range, or NULL, where that is not accepted).
-ENOMEM
Memory allocation failed.
NOTES
The sd_get_seats(), sd_get_sessions(), sd_get_uids() and sd_get_machine_names() interfaces are available
as a shared library, which can be compiled and linked to with the libsystemd pkg-config(1) file.
SEE ALSO
systemd(1), sd-login(3), sd_session_get_seat(3)
systemd 229 SD_GET_SEATS(3)