x SuSE Linux 13.1-RELEASE x
x SuSE Linux 13.1-RELEASEx
SD_UID_GET_STATE(3) sd_uid_get_state SD_UID_GET_STATE(3)
NAME
sd_uid_get_state, sd_uid_is_on_seat, sd_uid_get_sessions,
sd_uid_get_seats, sd_uid_get_display, sd_uid_get_login_time - Determine
login state of a specific Unix user ID
SYNOPSIS
#include <systemd/sd-login.h>
int sd_uid_get_state(uid_t uid, char **state);
int sd_uid_is_on_seat(uid_t uid, int require_active, const char *seat);
int sd_uid_get_sessions(uid_t uid, int require_active,
char ***sessions);
int sd_uid_get_seats(uid_t uid, int require_active, char ***seats);
int sd_uid_get_display(uid_t uid, char **session);
int sd_uid_get_login_time(uid_t uid, uint64_t *usec);
DESCRIPTION
sd_uid_get_state() may be used to determine the login state of a
specific Unix user identifier. The following states are currently
known: "offline" (user not logged in at all), "lingering" (user not
logged in, but some user services running), "online" (user logged in,
but not active, i.e. has no session in the foreground), "active" (user
logged in, and has at least one active session, i.e. one session in the
foreground), "closing" (user not logged in, and not lingering, but some
processes are still around). In the future additional states might be
defined, client code should be written to be robust in regards to
additional state strings being returned. The returned string needs to
be freed with the libc free(3) call after use.
sd_uid_is_on_seat() may be used to determine whether a specific user is
logged in or active on a specific seat. Accepts a Unix user identifier
and a seat identifier string as parameters. The require_active
parameter is a boolean value. If non-zero (true), this function will
test if the user is active (i.e. has a session that is in the
foreground and accepting user input) on the specified seat, otherwise
(false) only if the user is logged in (and possibly inactive) on the
specified seat.
sd_uid_get_sessions() may be used to determine the current sessions of
the specified user. Accepts a Unix user identifier as parameter. The
require_active parameter controls whether the returned list shall
consist of only those sessions where the user is currently active (>
0), where the user is currently online but possibly inactive (= 0), or
logged in but possibly closing the session (< 0). The call returns a
NULL terminated string array of session identifiers in sessions which
needs to be freed by the caller with the libc free(3) call after use,
including all the strings referenced. If the string array parameter is
passed as NULL, the array will not be filled in, but the return code
still indicates the number of current sessions. Note that instead of an
empty array NULL may be returned and should be considered equivalent to
an empty array.
Similarly, sd_uid_get_seats() may be used to determine the list of
seats on which the user currently has sessions. Similar semantics
apply, however note that the user may have multiple sessions on the
same seat as well as sessions with no attached seat and hence the
number of entries in the returned array may differ from the one
returned by sd_uid_get_sessions().
sd_uid_get_display() returns the name of the "primary" session of a
user. If the user has graphical sessions, it will be the oldest
graphical session. Otherwise, it will be the oldest open session.
sd_uid_get_login_time() may be used to determine the time the user's
service manager has been invoked, which is the time when the user's
first active session, since which they stayed logged in continuously,
began. The usec is in microseconds since the epoch (CLOCK_REALTIME).
This call will fail with -ENXIO if the user is not currently logged in.
RETURN VALUE
On success, sd_uid_get_state() and sd_uid_get_login_time() returns 0 or
a positive integer. If the test succeeds, sd_uid_is_on_seat() returns a
positive integer; if it fails, 0. sd_uid_get_sessions() and
sd_uid_get_seats() return the number of entries in the returned arrays.
sd_uid_get_display() returns a non-negative code on success. On
failure, these calls return a negative errno-style error code.
Errors
Returned errors may indicate the following problems:
-ENODATA
The given field is not specified for the described user.
-ENXIO
The specified seat is unknown.
-EINVAL
An input parameter was invalid (out of range, or NULL, where that
is not accepted). This is also returned if the passed user ID is
0xFFFF or 0xFFFFFFFF, which are undefined on Linux.
-ENOMEM
Memory allocation failed.
NOTES
Functions described here are available as a shared library, which can
be compiled against and linked to with the libsystemd pkg-config(1)
file.
The code described here uses getenv(3), which is declared to be not
multi-thread-safe. This means that the code calling the functions
described here must not call setenv(3) from a parallel thread. It is
recommended to only do calls to setenv() from an early phase of the
program when no other threads have been started.
SEE ALSO
systemd(1), sd-login(3), sd_pid_get_owner_uid(3)
systemd 254 SD_UID_GET_STATE(3)
Want to link to this manual page? Use this URL:
<http://star2.abcm.com/cgi-bin/bsdi-man?query=sd_uid_get_state&sektion=3&manpath=>