diff --git a/src/basename.c b/src/basename.c
index d3ac072..07f6906 100644
--- a/src/basename.c
+++ b/src/basename.c
@@ -7,8 +7,29 @@
 #include <string.h>
 
 
+/* basename */
+static int _basename(char * arg, char * suf)
+{
+	char * str;
+
+	str = basename(arg);
+	if(suf != NULL)
+	{
+		int slen;
+		int alen;
+
+		slen = strlen(str);
+		alen = strlen(suf);
+		if(alen < slen && strcmp(suf, &str[slen - alen]) == 0)
+			str[slen - alen] = '\0';
+	}
+	printf("%s\n", str);
+	return 0;
+}
+
+
 /* usage */
-static int usage(void)
+static int _usage(void)
 {
 	fprintf(stderr, "%s", "Usage: basename string [suffix]\n");
 	return 1;
@@ -18,23 +39,9 @@ static int usage(void)
 /* main */
 int main(int argc, char * argv[])
 {
-	char * str;
-
-	/* check for errors */
-	if(argc != 2 && argc != 3)
-		return usage();
-	/* basename */
-	str = basename(argv[1]);
+	if(argc == 2)
+		return _basename(argv[1], NULL);
 	if(argc == 3)
-	{
-		int slen;
-		int alen;
-
-		slen = strlen(str);
-		alen = strlen(argv[2]);
-		if(alen < slen && strcmp(argv[2], &str[slen - alen]) == 0)
-			str[slen - alen] = '\0';
-	}
-	printf("%s\n", str);
-	return 0;
+		return _basename(argv[1], argv[2]);
+	return _usage();
 }
diff --git a/src/dirname.c b/src/dirname.c
index 5f2f503..e7215f7 100644
--- a/src/dirname.c
+++ b/src/dirname.c
@@ -6,8 +6,16 @@
 #include <stdio.h>
 
 
+/* dirname */
+static int _dirname(char * arg)
+{
+	printf("%s\n", dirname(arg));
+	return 0;
+}
+
+
 /* usage */
-static int usage(void)
+static int _usage(void)
 {
 	fprintf(stderr, "%s", "Usage: dirname string\n");
 	return 1;
@@ -17,10 +25,7 @@ static int usage(void)
 /* main */
 int main(int argc, char * argv[])
 {
-	/* check for errors */
 	if(argc != 2)
-		return usage();
-	/* dirname */
-	printf("%s\n", dirname(argv[1]));
-	return 0;
+		return _usage();
+	return _dirname(argv[1]);
 }