Merge pull request #1 from jtsiomb/master

Minor kbdlight improvements.

Makefile

@@ -1,6 +1,19 @@
-all:
-	gcc kbdlight.c -o kbdlight
+PREFIX = /usr/local
+
+obj = kbdlight.o
+bin = kbdlight
+
+$(bin): $(obj)
+	$(CC) -o $@ $(obj) $(LDFLAGS)
+
+.PHONY: clean
 clean:
-	rm kbdlight
+	rm -f $(obj) $(bin)
+
+.PHONY: install
 install:
-	install -Dm 4755 kbdlight ${DESTDIR}/usr/bin/kbdlight
+	install -Dm 4755 $(bin) $(DESTDIR)$(PREFIX)/bin/$(bin)
+
+.PHONY: uninstall
+uninstall:
+	rm -f $(DESTDIR)$(PREFIX)/bin/$(bin)

kbdlight.c

@@ -2,23 +2,37 @@
 #include <stdlib.h>
 #include <string.h>
 
+#define BLPATH		"/sys/class/leds/smc::kbd_backlight"
+#define BLVALFILE	BLPATH "/brightness"
+#define BLMAXFILE	BLPATH "/max_brightness"
+
 void usage() {
-    printf("Usage: kbdlight [up|down|off|max]\n");
+    printf("Usage: kbdlight [up|down|off|max|get|set <value>]\n");
     exit(0);
 }
 
 int main(int argc, char* argv[]) {
-  int current, next;
+  int current, next, maxval;
   FILE *file;
 
-  if (argc != 2) {
+  if (argc < 2) {
     usage();
   }
 
-  file = fopen("/sys/class/leds/smc::kbd_backlight/brightness", "r");
+  if(!(file = fopen(BLVALFILE, "r"))) {
+    perror("failed to open the keyboard backlight file: " BLVALFILE);
+    return 1;
+  }
   fscanf(file, "%d", &current);
   fclose(file);
 
+  if((file = fopen(BLMAXFILE, "r"))) {
+    fscanf(file, "%d", &maxval);
+    fclose(file);
+  } else {
+    maxval = 255;
+  }
+
   if (!strcmp(argv[1], "up"))
     next = current + 16;
   else if (!strcmp(argv[1], "down"))
@@ -27,11 +41,23 @@ int main(int argc, char* argv[]) {
     next = 0;
   else if (!strcmp(argv[1], "max"))
     next = 255;
-  else
+  else if (!strcmp(argv[1], "set")) {
+    char *endp;
+    if(!argv[2] || (next = strtol(argv[2], &endp, 10), endp == argv[2])) {
+      fprintf(stderr, "set must be followed by a number from 0 to %d\n", maxval);
+      return 1;
+    }
+  } else if(!strcmp(argv[1], "get")) {
+    printf("%d\n", current);
+    return 0;
+  } else
     usage();
 
-  file = fopen("/sys/class/leds/smc::kbd_backlight/brightness", "w");
-  fprintf(file, "%d", next);
-  fclose(file);
+  if((file = fopen(BLVALFILE, "w"))) {
+    fprintf(file, "%d", next);
+    fclose(file);
+  } else {
+    perror("failed to write to the keyboard backlight file: " BLVALFILE);
+  }
   return 0;
 }