diff --git a/TODO b/TODO
index 5ee4076..0d7d367 100644
--- a/TODO
+++ b/TODO
@@ -52,3 +52,4 @@ FIX:
  xargs (-d)
  echo (escape)
  que (unicode)
+ ps (-o)
diff --git a/src/head.c b/src/head.c
index 8ac62b8..a6a982c 100644
--- a/src/head.c
+++ b/src/head.c
@@ -1,5 +1,12 @@
 #define _HEAD_C
 
+#ifdef _TAIL_C
+#define PROG_NAME "tail"
+#else
+#define PROG_NAME "head"
+#define _TAIL_C 0
+#endif
+
 #include <fcntl.h>
 #include <stdio.h>
 #include <errno.h>
@@ -16,10 +23,13 @@ static long parse_long(const char *str) {
 	char *ptr;
 	long ret = strtol(str, &ptr, 0);
 	if (*ptr) {
-		fprintf(stderr, "head: invalid number %s\n", ptr);
+		fprintf(stderr, "%s: invalid number %s\n", PROG_NAME, ptr);
 		exit(1);
 	}
 
+	if (_TAIL_C && ret < 0)
+		ret *= -1;
+
 	return ret;
 }
 
@@ -31,7 +41,7 @@ static int print(const char *file, FILE *fp, long lines, long bytes) {
 	long bcount = 0;
 
 	/* If lines or bytes < 0 */
-	if (lines < 0 || bytes < 0) {
+	if ((lines < 0 || bytes < 0) || _TAIL_C) {
 		long lmax = 0;
 		long bmax = 0;
 
@@ -39,10 +49,11 @@ static int print(const char *file, FILE *fp, long lines, long bytes) {
 		size_t buf_size = 0;
 		char *buf = malloc(1);
 		if (buf == NULL) {
-			fprintf(stderr, "head: malloc: %s\n", strerror(errno));
+			fprintf(stderr, "%s: malloc: %s\n", PROG_NAME, strerror(errno));
 			return 1;
 		}
 
+		/* Fill buffer */
 		while (1) {
 			int c = getc(fp);
 			if (c == EOF)
@@ -50,7 +61,7 @@ static int print(const char *file, FILE *fp, long lines, long bytes) {
 
 			char *tmp = realloc(buf, buf_size + 2);
 			if (tmp == NULL) {
-				fprintf(stderr, "head: realloc: %s\n", strerror(errno));
+				fprintf(stderr, "%s: realloc: %s\n", PROG_NAME, strerror(errno));
 
 				free(buf);
 				return 1;
@@ -72,9 +83,15 @@ static int print(const char *file, FILE *fp, long lines, long bytes) {
 				lcount++;
 
 			bcount++;
-			putchar(buf[i]);
-			if ((n_flag && lcount == lmax + lines) || (c_flag && bcount == bmax + bytes))
-				break;
+
+			if ((c_flag && bmax - bcount < bytes) || (n_flag && lmax - lcount < lines))
+				putchar(buf[i]);
+
+			else if (!_TAIL_C) {
+				putchar(buf[i]);
+				if ((n_flag && lcount == lmax + lines) || (c_flag && bcount == bmax + bytes))
+					break;
+			}
 		}
 
 		free(buf);
@@ -121,7 +138,7 @@ int main(int argc, char **argv) {
 				break;
 
 			default:
-				puts("head [ncv] [file1 file2...]\n\t-n Print [-]N lines\n\t-c Print [-]N bytes\n\t-v Print headers");
+				printf("%s [ncv] [file1 file2...]\n\t-n Print [-]N lines\n\t-c Print [-]N bytes\n\t-v Print headers\n", PROG_NAME);
 				return 0;
 		}
 	}
@@ -142,7 +159,7 @@ int main(int argc, char **argv) {
 			fp = fopen(argv[i], "r");
 
 		if (fp == NULL) {
-			fprintf(stderr, "head: %s: %s\n", argv[i], strerror(errno));
+			fprintf(stderr, "%s: %s: %s\n", PROG_NAME, argv[i], strerror(errno));
 
 			ret = 1;
 			continue;
diff --git a/src/tail.c b/src/tail.c
new file mode 100644
index 0000000..7d0d04e
--- /dev/null
+++ b/src/tail.c
@@ -0,0 +1,2 @@
+#define _TAIL_C 1
+#include "head.c"