f_executable(typval_T *argvars, typval_T *rettv)
{
    if (in_vim9script() && check_for_string_arg(argvars, 0) == FAIL)
	return;

    // Check in $PATH and also check directly if there is a directory name.
    rettv->vval.v_number = mch_can_exe(tv_get_string(&argvars[0]), NULL, TRUE);
}