Re: [PATCH] rtcwake: use poweroff if shutdown is not found

[Karel Zak <kzak@redhat.com>]

On Wed, Oct 31, 2018 at 12:25:48PM -0700, justinpopo6@gmail.com wrote:
> From: Justin Chen <justinpopo6@gmail.com>
> 
> Some systems do not have the shutdown command. Use poweroff as an
> alternative.
> 
> Signed-off-by: Justin Chen <justinpopo6@gmail.com>
> ---
>  include/pathnames.h |  1 +
>  sys-utils/rtcwake.c | 38 +++++++++++++++++++++++++++-----------
>  2 files changed, 28 insertions(+), 11 deletions(-)
> 
> diff --git a/include/pathnames.h b/include/pathnames.h
> index 3d5052e..ed8ea33 100644
> --- a/include/pathnames.h
> +++ b/include/pathnames.h
> @@ -53,6 +53,7 @@
>  # define _PATH_LOGIN		"/bin/login"
>  #endif
>  #define _PATH_SHUTDOWN		"/sbin/shutdown"
> +#define _PATH_POWEROFF		"/sbin/poweroff"
>  
>  #define _PATH_TERMCOLORS_DIRNAME "terminal-colors.d"
>  #define _PATH_TERMCOLORS_DIR	"/etc/" _PATH_TERMCOLORS_DIRNAME
> diff --git a/sys-utils/rtcwake.c b/sys-utils/rtcwake.c
> index b63c646..b79adbe 100644
> --- a/sys-utils/rtcwake.c
> +++ b/sys-utils/rtcwake.c
> @@ -28,6 +28,7 @@
>  #include <stdlib.h>
>  #include <string.h>
>  #include <sys/ioctl.h>
> +#include <sys/stat.h>
>  #include <sys/time.h>
>  #include <sys/types.h>
>  #include <termios.h>
> @@ -579,20 +580,35 @@ int main(int argc, char **argv)
>  		break;
>  	case OFF_MODE:
>  	{
> +		struct stat buf;
>  		char *arg[5];
>  		int i = 0;
>  
> -		if (ctl.verbose)
> -			printf(_("suspend mode: off; executing %s\n"),
> -						_PATH_SHUTDOWN);
> -		arg[i++] = _PATH_SHUTDOWN;
> -		arg[i++] = "-h";
> -		arg[i++] = "-P";
> -		arg[i++] = "now";
> -		arg[i]   = NULL;
> -		if (!ctl.dryrun) {
> -			execv(arg[0], arg);
> -			warn(_("failed to execute %s"), _PATH_SHUTDOWN);
> +		if (!stat(_PATH_SHUTDOWN, &buf)) {

 what about   if (access(_PATH_SHUTDOWN, X_OK) == 0) to avoid copy
 unnecessary struct stat from kernel to userspace? ;-)

    Karel

> +			arg[i++] = _PATH_SHUTDOWN;
> +			arg[i++] = "-h";
> +			arg[i++] = "-P";
> +			arg[i++] = "now";
> +			arg[i]   = NULL;
> +		} else if (!stat(_PATH_POWEROFF, &buf)) {
> +			arg[i++] = _PATH_POWEROFF;
> +			arg[i]   = NULL;
> +		} else {
> +			arg[i] 	 = NULL;
> +		}
> +
> +		if (arg[0]) {
> +			if (ctl.verbose)
> +				printf(_("suspend mode: off; executing %s\n"),
> +						arg[0]);
> +			if (!ctl.dryrun) {
> +				execv(arg[0], arg);
> +				warn(_("failed to execute %s"), arg[0]);
> +				rc = EXIT_FAILURE;
> +			}
> +		} else {
> +			/* Failed to find shutdown command */
> +			warn(_("failed to find shutdown command"));
>  			rc = EXIT_FAILURE;
>  		}
>  		break;
> -- 
> 2.7.4
> 

-- 
 Karel Zak  <kzak@redhat.com>
 http://karelzak.blogspot.com