sbase

commit 2a83c2c8bef7f0e48d575e14d49aa22e44b649dd
parent 6b63fc2f2bcf55d61ab81a4ae6282e563b6b07aa
Author: FRIGN <dev@frign.de>
Date:   Mon,  9 Feb 2015 15:06:17 +0100

Add f-flag to tail(1) and refactor code

Diffstat:
M
tail.c
 | 
119
++++++++++++++++++++++++++++++++++++++++++++++---------------------------------

1 file changed, 69 insertions(+), 50 deletions(-)
diff --git a/tail.c b/tail.c
@@ -8,26 +8,68 @@
 #include "text.h"
 #include "util.h"
 
-static void dropinit(FILE *, const char *, long);
-static void taketail(FILE *, const char *, long);
+static int fflag = 0;
+
+static void
+dropinit(FILE *fp, const char *str, long n)
+{
+	char *buf = NULL;
+	size_t size = 0;
+	ssize_t len;
+	unsigned long i = 0;
+
+	while (i < n && (len = getline(&buf, &size, fp)) != -1)
+		if (len > 0 && buf[len - 1] == '\n')
+			i++;
+	free(buf);
+	concat(fp, str, stdout, "<stdout>");
+}
+
+static void
+taketail(FILE *fp, const char *str, long n)
+{
+	char **ring = NULL;
+	long i, j;
+	size_t *size = NULL;
+
+	ring = ecalloc(n, sizeof *ring);
+	size = ecalloc(n, sizeof *size);
+
+	for (i = j = 0; getline(&ring[i], &size[i], fp) != -1; i = j = (i + 1) % n)
+		;
+	if (ferror(fp))
+		eprintf("%s: read error:", str);
+
+	do {
+		if (ring[j]) {
+			fputs(ring[j], stdout);
+			free(ring[j]);
+		}
+	} while ((j = (j + 1) % n) != i);
+
+	free(ring);
+	free(size);
+}
 
 static void
 usage(void)
 {
-	eprintf("usage: %s [-n lines] [file]\n", argv0);
+	eprintf("usage: %s [-f] [-n lines] [file ...]\n", argv0);
 }
 
 int
 main(int argc, char *argv[])
 {
-	long n = 10;
 	FILE *fp;
+	size_t n = 10, tmpsize;
+	int ret = 0, newline, many;
+	char *lines, *tmp;
 	void (*tail)(FILE *, const char *, long) = taketail;
-	char *lines;
-	int ret = 0;
-	int newline, many;
 
 	ARGBEGIN {
+	case 'f':
+		fflag = 1;
+		break;
 	case 'n':
 		lines = EARGF(usage());
 		n = estrtonum(lines, 0, LONG_MAX);
@@ -40,10 +82,12 @@ main(int argc, char *argv[])
 	default:
 		usage();
 	} ARGEND;
-	if (argc == 0) {
+
+	if (argc == 0)
 		tail(stdin, "<stdin>", n);
-	} else {
-		many = argc > 1;
+	else {
+		if ((many = argc > 1) && fflag)
+			usage();
 		for (newline = 0; argc > 0; argc--, argv++) {
 			if (!(fp = fopen(argv[0], "r"))) {
 				weprintf("fopen %s:", argv[0]);
@@ -55,48 +99,23 @@ main(int argc, char *argv[])
 				       newline ? "\n" : "", argv[0]);
 			newline = 1;
 			tail(fp, argv[0], n);
+
+			if (fflag && argc == 1) {
+				for(;; tmp = NULL, tmpsize = 0) {
+					while (getline(&tmp, &tmpsize, fp) != -1) {
+						fputs(tmp, stdout);
+						fflush(stdout);
+						free(tmp);
+						tmp = NULL;
+						tmpsize = 0;
+					}
+					if (ferror(fp))
+						eprintf("readline '%s':", argv[0]);
+					clearerr(fp);
+				}
+			}
 			fclose(fp);
 		}
 	}
 	return ret;
 }
-
-static void
-dropinit(FILE *fp, const char *str, long n)
-{
-	char *buf = NULL;
-	size_t size = 0;
-	ssize_t len;
-	unsigned long i = 0;
-
-	while (i < n && ((len = getline(&buf, &size, fp)) != -1))
-		if (len && buf[len - 1] == '\n')
-			i++;
-	free(buf);
-	concat(fp, str, stdout, "<stdout>");
-}
-
-static void
-taketail(FILE *fp, const char *str, long n)
-{
-	char **ring = NULL;
-	long i, j;
-	size_t *size = NULL;
-
-	ring = ecalloc(n, sizeof *ring);
-	size = ecalloc(n, sizeof *size);
-
-	for (i = j = 0; getline(&ring[i], &size[i], fp) != -1; i = j = (i + 1) % n)
-		;
-	if (ferror(fp))
-		eprintf("%s: read error:", str);
-
-	do {
-		if (ring[j]) {
-			fputs(ring[j], stdout);
-			free(ring[j]);
-		}
-	} while ((j = (j+1)%n) != i);
-	free(ring);
-	free(size);
-}