fixed head

TODO

@@ -50,6 +50,5 @@ BUGS:
 
 FIX:
  ps
- head
  echo (escape)
  que (unicode)

src/coreutils/head/head.c

@@ -10,46 +10,102 @@
 
 char v_flag;
 char c_flag;
+char n_flag;
 
 long parse_long(const char *str) {
 	char *ptr;
 	long ret = strtol(str, &ptr, 0);
 	if (*ptr) {
-		fprintf(stderr, "head: %s invalid number\n", ptr);
+		fprintf(stderr, "head: invalid number %s\n", ptr);
 		exit(1);
 	}
 
 	return ret;
 }
 
-void print(const char *file, FILE *fp, long lines, long bytes) {
+int print(const char *file, FILE *fp, long lines, long bytes) {
 	if (v_flag)
 		printf(HEAD_FMT, file);
 
 	long lcount = 0;
 	long bcount = 0;
 
+	/* If lines or bytes < 0 */
+	if (lines < 0 || bytes < 0) {
+		long lmax = 0;
+		long bmax = 0;
+
+		size_t buf_size = 0;
+		char *buf = malloc(1);
+		if (buf == NULL) {
+			fprintf(stderr, "head: malloc: %s\n", strerror(errno));
+			return 1;
+		}
+
 		while (1) {
 			int c = getc(fp);
-		bcount++;
+			if (c == EOF)
-		if (c == '\n')
-			lcount++;
-
-		if (c == EOF || lcount == lines || (c_flag && bcount == bytes))
 				break;
 
-		putchar(c);
+			char *tmp = realloc(buf, buf_size + 2);
+			if (tmp == NULL) {
+				fprintf(stderr, "head: realloc: %s\n", strerror(errno));
+
+				free(buf);
+				return 1;
 			}
+
+			buf = tmp;
+			buf[buf_size] = c;
+			if (c == '\n')
+				lmax++;
+			bmax++;
+			buf_size++;
+		}
+
+		buf[buf_size] = '\0';
+
+		for (size_t i = 0; i < buf_size; i++) {
+			if (buf[i] == '\n')
+				lcount++;
+
+			bcount++;
+			putchar(buf[i]);
+			if ((n_flag && lcount == lmax + lines) || (c_flag && bcount == bmax + bytes))
+				break;
+		}
+
+		free(buf);
+	}
+
+	else {
+		while (1) {
+			int c = getc(fp);
+			if (c == EOF)
+				break;
+
+			if (c == '\n')
+				lcount++;
+			bcount++;
+			putchar(c);
+
+			if ((n_flag && lcount == lines) || (c_flag && bcount == bytes))
+				break;
+		}
+	}
+
+	return 0;
 }
 
 int main(int argc, char **argv) {
-	long lines = 10;
+	long lines = 0;
 	long bytes = 0;
 
 	int opt;
 	while ((opt = getopt(argc, argv, "n:c:v")) != -1) {
 		switch (opt) {
 			case 'n':
+				n_flag = 1;
 				lines = parse_long(optarg);
 				break;
 
@@ -63,7 +119,7 @@ int main(int argc, char **argv) {
 				break;
 
 			default:
-				printf("head [ncv] [file1 file2...]\n\t-n Print N lines\n\t-c Print N bytes\n\t-v Print headers\n");
+				printf("head [ncv] [file1 file2...]\n\t-n Print [-]N lines\n\t-c Print [-]N bytes\n\t-v Print headers\n");
 				return 0;
 		}
 	}
@@ -74,6 +130,7 @@ int main(int argc, char **argv) {
 	if (argc == 0)
 		print("-", stdin, lines, bytes);
 
+	int ret = 0;
 	for (int i = 0; i < argc; i++) {
 		FILE *fp = NULL;
 		if (argv[i][0] == '-')
@@ -84,10 +141,14 @@ int main(int argc, char **argv) {
 
 		if (fp == NULL) {
 			fprintf(stderr, "head: %s: %s\n", argv[i], strerror(errno));
-			return 1;
+
+			ret = 1;
+			continue;
 		}
 
-		print(argv[i], fp, lines, bytes);
+		if (print(argv[i], fp, lines, bytes))
+			ret = 1;
+
 		fclose(fp);
 	}