strcmp(1): re-style, tweak exits

src/strcmp.c

@@ -17,26 +17,26 @@
  */
 
 #include <stdio.h> /* fprintf(3), stderr */
-#include <stdlib.h> /* EXIT_FAILURE */
+#include <stdlib.h> /* size_t */
 #include <sysexits.h> /* EX_USAGE */
 
-static char *program_name = "strcmp";
+static *program_name = "strcmp";
 
 int main(int argc, char *argv[]){
-	int i;
-
 	if (argc < 3) {
 		fprintf(stderr, "Usage: %s string string...\n",
-			argv[0] == NULL ? program_name : argv[0]);
+			argv[0] == NULL ? program_name : argv[0]
+		);
 		return EX_USAGE;
 	}
 
-	for(; *argv[1] != '\0'; ++argv[1])
-		for(i = 2; i < argc; ++i)
-			if(*argv[i-1] > *argv[i])
-				return 1;
-			else if(*argv[i-1] < *argv[i]++)
-				return -1; /* actually 255 */
+	for (; *argv[1] != '\0'; ++argv[1]) { /* iterate chars in ref */
+		/* iterate argc */
+		for (size_t i = 2 /* ref cmp */; i < argc; ++argv[i], ++i) {
+			/* this doesn't overrun because of nul termination */
+			if (*argv[i-1] != *argv[i]) { return *argv[i-1] - *argv[i]; }
+		}
+	}
 
 	return 0;
 }