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 the number of seat
       identifiers and if the input pointer is non-NULL, a NULL-terminated array of seat identifiers is stored
       at the address. 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:

       -ENOMEM
           Memory allocation failed.

NOTES

       These APIs are implemented 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)