strcmp(1): returns -1, specifies sysexits imports

src/strcmp.c

@@ -18,7 +18,7 @@
  */
 
 #include <stdio.h> /* fprintf(3), stderr */
-#include <sysexits.h>
+#include <sysexits.h> /* EX_OK, EX_USAGE */
 
 static char *program_name = "strcmp";
 
@@ -40,7 +40,7 @@ int main(int argc, char *argv[]) {
 			if (*argv[i-1] > *argv[i]) {
 				return 1;
 			} else if (*argv[i-1] < *argv[i]++) {
-				return 255;
+				return -1; /* actually 255 */
 			}
 		}
 	}