systemd Developer Lennart Poettering lennart@poettering.net sd_session_is_active 3 sd_session_is_active sd_session_get_uid sd_session_get_seat sd_session_get_service 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 int sd_session_get_service const char* session char** service 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. 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 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(), sd_session_get_service() 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(), sd_session_get_service() 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