sd_get_uids(3) Determine available seats, sessions, logged in users and virtual machines/containers

Other Alias

sd_get_seats, sd_get_sessions, sd_get_machine_names

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

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