|
NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | NOTES | SEE ALSO | NOTES | COLOPHON |
SD_SESSION_IS_ACTIVE(3) sd_session_is_active SD_SESSION_IS_ACTIVE(3)
sd_session_is_active, sd_session_is_remote, sd_session_get_state,
sd_session_get_uid, sd_session_get_seat, sd_session_get_service,
sd_session_get_type, sd_session_get_class, sd_session_get_desktop,
sd_session_get_display, sd_session_get_tty, sd_session_get_vt,
sd_session_get_remote_host, sd_session_get_remote_user - Determine
state of a specific session
#include <systemd/sd-login.h>
int sd_session_is_active(const char *session);
int sd_session_is_remote(const char *session);
int sd_session_get_state(const char *session, char **state);
int sd_session_get_uid(const char *session, uid_t *uid);
int sd_session_get_seat(const char *session, char **seat);
int sd_session_get_service(const char *session, char **service);
int sd_session_get_type(const char *session, char **type);
int sd_session_get_class(const char *session, char **class);
int sd_session_get_desktop(const char *session, char **desktop);
int sd_session_get_display(const char *session, char **display);
int sd_session_get_remote_host(const char *session,
char **remote_host);
int sd_session_get_remote_user(const char *session,
char **remote_user);
int sd_session_get_tty(const char *session, char **tty);
int sd_session_get_vt(const char *session, unsigned int *vt);
sd_session_is_active() may be used to determine whether the session
identified by the specified session identifier is currently active
(i.e. currently in the foreground and available for user input) or
not.
sd_session_is_remote() may be used to determine whether the session
identified by the specified session identifier is a remote session
(i.e. its remote host is known) or not.
sd_session_get_state() may be used to determine the state of the
session identified by the specified session identifier. The following
states are currently known: "online" (session logged in, but session
not active, i.e. not in the foreground), "active" (session logged in
and active, i.e. in the foreground), "closing" (session nominally
logged out, but some processes belonging to it 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. This function is a more generic version of
sd_session_is_active(). The returned string needs to be freed with
the libc free(3) call after use.
sd_session_get_uid() may be used to determine the user identifier of
the Unix user the session identified by the specified session
identifier belongs to.
sd_session_get_seat() may be used to determine the seat identifier of
the seat the session identified by the specified session identifier
belongs to. Note that not all sessions are attached to a seat, this
call will fail (returning -ENODATA) for them. The returned string
needs to be freed with the libc free(3) call after use.
sd_session_get_service() may be used to determine the name of the
service (as passed during PAM session setup) that registered the
session identified by the specified session identifier. The returned
string needs to be freed with the libc free(3) call after use.
sd_session_get_type() may be used to determine the type of the
session identified by the specified session identifier. The returned
string is one of "x11", "wayland", "tty", "mir" or "unspecified" and
needs to be freed with the libc free(3) call after use.
sd_session_get_class() may be used to determine the class of the
session identified by the specified session identifier. The returned
string is one of "user", "greeter", "lock-screen", or "background"
and needs to be freed with the libc free(3) call after use.
sd_session_get_desktop() may be used to determine the brand of the
desktop running on the session identified by the specified session
identifier. This field can be set freely by desktop environments and
does not follow any special formatting. However, desktops are
strongly recommended to use the same identifiers and capitalization
as for $XDG_CURRENT_DESKTOP, as defined by the Desktop Entry
Specification[1]. The returned string needs to be freed with the libc
free(3) call after use.
sd_session_get_display() may be used to determine the X11 display of
the session identified by the specified session identifier. The
returned string needs to be freed with the libc free(3) call after
use.
sd_session_get_remote_host() may be used to determine the remote
hostname of the session identified by the specified session
identifier. The returned string needs to be freed with the libc
free(3) call after use.
sd_session_get_remote_user() may be used to determine the remote
username of the session identified by the specified session
identifier. The returned string needs to be freed with the libc
free(3) call after use. Note that this value is rarely known to the
system, and even then should not be relied on.
sd_session_get_tty() may be used to determine the TTY device of the
session identified by the specified session identifier. The returned
string needs to be freed with the libc free(3) call after use.
sd_session_get_vt() may be used to determine the VT number of the
session identified by the specified session identifier. This function
will return an error if the seat does not support VTs.
If the session parameter of any of these functions is passed as NULL,
the operation is executed for the session the calling process is a
member of, if there is any.
If the test succeeds, sd_session_is_active() and
sd_session_is_remote() return a positive integer; if it fails, 0. On
success, sd_session_get_state(), sd_session_get_uid(),
sd_session_get_seat(), sd_session_get_service(),
sd_session_get_type(), sd_session_get_class(),
sd_session_get_display(), sd_session_get_remote_user(),
sd_session_get_remote_host() and sd_session_get_tty() return 0 or a
positive integer. On failure, these calls return a negative
errno-style error code.
Returned errors may indicate the following problems:
-ENXIO
The specified session does not exist.
-ENODATA
The given field is not specified for the described session.
-EINVAL
An input parameter was invalid (out of range, or NULL, where that
is not accepted).
-ENOMEM
Memory allocation failed.
The sd_session_is_active(), sd_session_get_state(),
sd_session_get_uid(), sd_session_get_seat(),
sd_session_get_service(), sd_session_get_type(),
sd_session_get_class(), sd_session_get_display(),
sd_session_get_remote_host(), sd_session_get_remote_user() and
sd_session_get_tty() interfaces are available as a shared library,
which can be compiled and linked to with the libsystemd pkg-config(1)
file.
systemd(1), sd-login(3), sd_pid_get_session(3)
1. Desktop Entry Specification
http://standards.freedesktop.org/desktop-entry-spec/latest/
This page is part of the systemd (systemd system and service manager)
project. Information about the project can be found at
⟨http://www.freedesktop.org/wiki/Software/systemd⟩. If you have a bug
report for this manual page, see
⟨http://www.freedesktop.org/wiki/Software/systemd/#bugreports⟩. This
page was obtained from the project's upstream Git repository
⟨https://github.com/systemd/systemd.git⟩ on 2017-07-05. If you dis‐
cover any rendering problems in this HTML version of the page, or you
believe there is a better or more up-to-date source for the page, or
you have corrections or improvements to the information in this
COLOPHON (which is not part of the original manual page), send a mail
to man-pages@man7.org
systemd 234 SD_SESSION_IS_ACTIVE(3)
Pages that refer to this page: sd_get_seats(3), sd-login(3), sd_pid_get_session(3), sd_seat_get_active(3), systemd.directives(7), systemd.index(7), pam_systemd(8)