1 files changed, 51 insertions, 40 deletions
diff --git a/crypt.c b/crypt.c
index 54b90ce..5e13fbd 100644
--- a/crypt.c
+++ b/crypt.c
@@ -1,45 +1,56 @@
 #include "crypt.h"
 
-/*
- * Main function
- */
 int main (int argc, char **argv)
 {
-    /* The hash we will produce, hopefully */
-    char *hash = NULL;
-
-    /* Assume user doesn't want help */
-    int help = 0;
-
-    /* Iterate through any options */
-    int o;
-    while ((o = getopt(argc, argv, OPTSTRING)) != -1) {
-        switch (o) {
-            case 'h':
-                help = 1;
-                break;
-            case '?':
-                fprintf(stderr, "Unknown option\n");
-                break;
-            default:
-                abort();
-        }
-    }
-
-    /* If help was asked, give it */
-    if (help) {
-        fprintf(stdout, "%s\n", USAGE);
-        exit(EXIT_SUCCESS);
-    }
-
-    /* If we don't have three arguments, bail */
-    if (argc != 3) {
-        fprintf(stderr, "%s\n", USAGE);
-        exit(EXIT_FAILURE);
-    }
-
-    /* All seems well, build the hash and print it */
-    hash = crypt(argv[1], argv[2]);
-    fprintf(stdout, "%s\n", hash);
-    exit(EXIT_SUCCESS);
+	char *hash, *key, *salt;
+	int opt;
+
+	while ((opt = getopt(argc, argv, "h")) != -1) {
+		switch (opt) {
+			case 'h': /* Help */
+				usage(stdout, EXIT_SUCCESS);
+				break;
+			case '?': /* Unknown option */
+				usage(stderr, EXIT_FAILURE);
+				break;
+			default: /* Shouldn't happen */
+				abort();
+		}
+	}
+
+	/*
+	 * If we don't have three arguments left after processing the options,
+	 * exit with usage information and error status
+	 */
+	if (argc != 3)
+		usage(stderr, EXIT_FAILURE);
+
+	key = argv[1];
+	salt = argv[2];
+
+	/*
+	 * Create the hash, but exit immediately with the system error string
+	 * if it returns a null pointer (error condition)
+	 */
+	if (!(hash = crypt(key, salt)))
+		error(strerror(errno));
+
+	puts(hash);
+	exit(EXIT_SUCCESS);
+}
+
+/*
+ * Show usage to given stream, and exit with given code
+ */
+void usage(FILE *stream, int status) {
+	fputs("USAGE: crypt [-h | KEY SALT]\n", stream);
+	exit(status);
+}
+
+/*
+ * Exit with error error message
+ */
+void error(char *message) {
+	fprintf(stderr, "%s\n", message);
+	exit(EXIT_FAILURE);
 }