Add -version option to print program version

Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>

2 files changed, 13 insertions, 0 deletions

diff --git a/man/xbacklight.man b/man/xbacklight.man
index c3aa48e..5a10d6a 100644
--- a/man/xbacklight.man
+++ b/man/xbacklight.man
@@ -46,6 +46,8 @@ Increases brightness by the specified amount.
 Decreases brightness by the specified amount.
 .IP \-help
 Print out a summary of the usage and exit.
+.IP \-version
+Print out the program version and exit.
 .IP "\-time \fImilliseconds\fP"
 Length of time to spend fading the backlight between old and new value.
 Default is 200.
diff --git a/xbacklight.c b/xbacklight.c
index 4f384cc..21cca72 100644
--- a/xbacklight.c
+++ b/xbacklight.c
@@ -19,6 +19,11 @@
  * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
  * OF THIS SOFTWARE.
  */
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
 #include <stdio.h>
 #include <stdlib.h>
 
@@ -44,6 +49,7 @@ usage (int exitcode)
             "  where options are:\n"
             "  -display <display> or -d <display>\n"
             "  -help\n"
+            "  -version\n"
             "  -set <percentage> or = <percentage>\n"
             "  -inc <percentage> or + <percentage>\n"
             "  -dec <percentage> or - <percentage>\n"
@@ -200,6 +206,11 @@ main (int argc, char **argv)
 	{
 	    usage (0);
 	}
+	if (!strcmp (argv[i], "-version"))
+	{
+	    puts (PACKAGE_STRING);
+	    exit (0);
+	}
 	fprintf(stderr, "%s: unrecognized argument '%s'\n",
 		program_name, argv[i]);
 	usage (1);