sd_session_is_active(3) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | NOTES | SEE ALSO | NOTES | COLOPHON

SD_SESSION_IS_ACTIVE(3)   sd_session_is_active   SD_SESSION_IS_ACTIVE(3)

NAME         top

       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

SYNOPSIS         top

       #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);

DESCRIPTION         top

       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.

RETURN VALUE         top

       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.

   Errors
       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.

NOTES         top

       These APIs are implemented as a shared library, which can be
       compiled and linked to with the libsystemd pkg-config(1) file.

SEE ALSO         top

       systemd(1), sd-login(3), sd_pid_get_session(3)

NOTES         top

        1. Desktop Entry Specification
           http://standards.freedesktop.org/desktop-entry-spec/latest/

COLOPHON         top

       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 2021-04-01.  (At that
       time, the date of the most recent commit that was found in the
       repository was 2021-04-01.)  If you discover 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 248                                      SD_SESSION_IS_ACTIVE(3)

Pages that refer to this page: sd_get_seats(3)sd-login(3)sd_pid_get_owner_uid(3)sd_seat_get_active(3)org.freedesktop.login1(5)systemd.directives(7)systemd.index(7)pam_systemd(8)