systemd Developer Lennart Poettering lennart@poettering.net sd_session_is_active 3 sd_session_is_active sd_session_get_uid sd_session_get_seat Determine state of a specific session #include <systemd/sd-login.h> int sd_session_is_active const char* session int sd_session_get_uid const char* session uid_t* uid int sd_session_get_seat const char* session char** seat 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_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 for them. The returned string needs to be freed with the libc free3 call after use. If the test succeeds sd_session_is_active() returns a positive integer, if it fails 0. On success sd_session_get_uid() and sd_session_get_seat() return 0 or a positive integer. On failure, these calls return a negative errno-style error code. The sd_session_is_active(), sd_session_get_uid(), and sd_session_get_seat() interfaces are available as shared library, which can be compiled and linked to with the libsystemd-login pkg-config1 file. systemd1, sd-login7, sd_pid_get_session3