sd_get_seats(3)

.SH "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

.SH "SYNOPSIS"

#include <systemd/sd-login.h>

.HP 408u int sd_get_seats(char ***seats);

.HP 480u int sd_get_sessions(char ***sessions);

.HP 384u int sd_get_uids(uid_t **users);

.HP 600u int sd_get_machine_names(char ***machines);

.SH "DESCRIPTION"

.PP 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.

.PP Similarly, sd_get_sessions() may be used to determine all current login sessions.

.PP Similarly, sd_get_uids() may be used to determine all Unix users who currently have login sessions.

.PP Similarly, sd_get_machine_names() may be used to determine all current virtual machines and containers on the system.

.PP Note that the returned lists are not sorted and in an undefined order.

.SH "RETURN VALUE"

.PP 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.

.SS "Errors"

.PP Returned errors may indicate the following problems:

.PP -ENOMEM