tail(1p): trying from scratch

src/tail.c

@@ -23,23 +23,11 @@
 #include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <unistd.h>
 
 #include "yac.h"
 
-void tailc(FILE *file, long num) {
-	int byte;
-	char buf[num];
-	long offset = -num;
-
-	fseek(file, offset, SEEK_END);
-	for (int i = 0; (byte = fgetc(file)) != EOF; i++) {
-		buf[i] = byte;
-	}
-
-	fputs(buf, stdout);
-}
-
 void tailf(FILE *file) {
 	int byte;
 
@@ -48,44 +36,6 @@ void tailf(FILE *file) {
 	}
 }
 
-void tailn(FILE *file, long num) {
-	char *buf = calloc(4096, 1);
-	char *lines[num];
-	int byte;
-	int lc = 0;
-
-	for (int bc = 0; (byte = fgetc(file)) != EOF; bc++) {
-		if (bc == sizeof(buf)) {
-			int err;
-			if (err = realloc(buf, sizeof(buf) * 2) == NULL) {
-				// TODO: error handling
-			}
-		}
-
-		buf[bc] = byte;
-
-		if (byte == '\n') {
-			lines[lc] = buf;
-			bc = 0;
-			lc++;
-		}
-
-		if (lc == num) {
-			for (int i = 0; i < lc; i++) {
-				lines[i] = lines[i + 1];
-			}
-			lc--;
-		}
-	}
-
-	int i;
-	if ((i = lc - num) < 0) { i = 0; }
-
-	for (; i < lc; i++) {
-		fputs(lines[i], stdout);
-	}
-}
-
 int main(int argc, char *argv[]) {
 	bool c = false;
 	bool f = false;
@@ -140,13 +90,13 @@ int main(int argc, char *argv[]) {
 			case 'c':
 				c = true;
 				fn = tailc;
-				num = (long)optarg;
+				num = strtol(optarg, NULL, 10);
 				break;
 			case 'f':
 				f = true;
 			case 'n':
 				n = true;
-				num = (long)optarg;
+				num = strtol(optarg, NULL, 10);
 				break;
 			default:
 				fprintf(
@@ -179,10 +129,10 @@ int main(int argc, char *argv[]) {
 		for (i = optind; i < argc; i++) {
 			if ((file = rpath(argv[0], argv[i])) != NULL) {
 				fn(file, num);
-				fclose(file);
 			}
 
 			if (f) { tailf(file); }
+			fclose(file);
 		}
 	}
 	return EX_OK;