X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=coreutils%2Fhead.c;h=ac476d09199e93b9967b20202c9b921eb8e353f1;hb=6b1e3d7e734f85a08c2e4414764f03a7f880b3e6;hp=688c250b16fd54fbc8025f42259736638a439015;hpb=2338d3176bdb6fb607a8ce81534e88522d8c516c;p=oweals%2Fbusybox.git

diff --git a/coreutils/head.c b/coreutils/head.c
index 688c250b1..ac476d091 100644
--- a/coreutils/head.c
+++ b/coreutils/head.c
@@ -1,97 +1,140 @@
 /* vi: set sw=4 ts=4: */
 /*
- * Mini head implementation for busybox
+ * head implementation for busybox
  *
+ * Copyright (C) 2003  Manuel Novoa III  <mjn3@codepoet.org>
  *
- * Copyright (C) 1999,2000,2001 by Lineo, inc.
- * Written by John Beppu <beppu@lineo.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- *
+ * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
  */
 
-#include <stdio.h>
-#include <getopt.h>
-#include <stdlib.h>
-#include <string.h>
-#include "busybox.h"
+/* BB_AUDIT SUSv3 compliant */
+/* BB_AUDIT GNU compatible -c, -q, and -v options in 'fancy' configuration. */
+/* http://www.opengroup.org/onlinepubs/007904975/utilities/head.html */
 
-static int head(int len, FILE *fp)
-{
-	int i;
-	char *input;
+#include "libbb.h"
 
-	for (i = 0; i < len; i++) {
-		if ((input = get_line_from_file(fp)) == NULL)
-			break;
-		fputs(input, stdout);
-		free(input);
-	}
-	return 0;
-}
+static const char head_opts[] ALIGN1 =
+	"n:"
+#if ENABLE_FEATURE_FANCY_HEAD
+	"c:qv"
+#endif
+	;
+
+#if ENABLE_FEATURE_FANCY_HEAD
+static const struct suffix_mult head_suffixes[] = {
+	{ "b", 512 },
+	{ "k", 1024 },
+	{ "m", 1024*1024 },
+	{ }
+};
+#endif
 
-/* BusyBoxed head(1) */
+static const char header_fmt_str[] ALIGN1 = "\n==> %s <==\n";
+
+int head_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int head_main(int argc, char **argv)
 {
+	unsigned long count = 10;
+	unsigned long i;
+#if ENABLE_FEATURE_FANCY_HEAD
+	int count_bytes = 0;
+	int header_threshhold = 1;
+#endif
 	FILE *fp;
-	int need_headers, opt, len = 10, status = EXIT_SUCCESS;
+	const char *fmt;
+	char *p;
+	int opt;
+	int c;
+	int retval = EXIT_SUCCESS;
+
+#if ENABLE_INCLUDE_SUSv2 || ENABLE_FEATURE_FANCY_HEAD
+	/* Allow legacy syntax of an initial numeric option without -n. */
+	if (argv[1] && argv[1][0] == '-'
+	 && isdigit(argv[1][1])
+	) {
+		--argc;
+		++argv;
+		p = (*argv) + 1;
+		goto GET_COUNT;
+	}
+#endif
 
-	/* parse argv[] */
-	while ((opt = getopt(argc, argv, "n:")) > 0) {
+	/* No size benefit in converting this to getopt32 */
+	while ((opt = getopt(argc, argv, head_opts)) > 0) {
 		switch (opt) {
+#if ENABLE_FEATURE_FANCY_HEAD
+		case 'q':
+			header_threshhold = INT_MAX;
+			break;
+		case 'v':
+			header_threshhold = -1;
+			break;
+		case 'c':
+			count_bytes = 1;
+			/* fall through */
+#endif
 		case 'n':
-			len = atoi(optarg);
-			if (len >= 1)
-				break;
-			/* fallthrough */
+			p = optarg;
+#if ENABLE_INCLUDE_SUSv2 || ENABLE_FEATURE_FANCY_HEAD
+ GET_COUNT:
+#endif
+#if !ENABLE_FEATURE_FANCY_HEAD
+			count = xatoul(p);
+#else
+			count = xatoul_sfx(p, head_suffixes);
+#endif
+			break;
 		default:
-			show_usage();
+			bb_show_usage();
 		}
 	}
 
-	/* get rest of argv[] or stdin if nothing's left */
-	if (argv[optind] == NULL) {
-		head(len, stdin);
-		return status;
-	} 
+	argc -= optind;
+	argv += optind;
+	if (!*argv)
+		*--argv = (char*)"-";
 
-	need_headers = optind != (argc - 1);
-	while (argv[optind]) {
-		if (strcmp(argv[optind], "-") == 0) {
-			fp = stdin;
-			argv[optind] = "standard input";
-		} else {
-			if ((fp = wfopen(argv[optind], "r")) == NULL)
-				status = EXIT_FAILURE;
-		}
+	fmt = header_fmt_str + 1;
+#if ENABLE_FEATURE_FANCY_HEAD
+	if (argc <= header_threshhold) {
+		header_threshhold = 0;
+	}
+#else
+	if (argc <= 1) {
+		fmt += 11; /* "" */
+	}
+	/* Now define some things here to avoid #ifdefs in the code below.
+	 * These should optimize out of the if conditions below. */
+#define header_threshhold   1
+#define count_bytes         0
+#endif
+
+	do {
+		fp = fopen_or_warn_stdin(*argv);
 		if (fp) {
-			if (need_headers) {
-				printf("==> %s <==\n", argv[optind]);
+			if (fp == stdin) {
+				*argv = (char *) bb_msg_standard_input;
+			}
+			if (header_threshhold) {
+				printf(fmt, *argv);
 			}
-			head(len, fp);
-			if (ferror(fp)) {
-				perror_msg("%s", argv[optind]);
-				status = EXIT_FAILURE;
+			i = count;
+			while (i && ((c = getc(fp)) != EOF)) {
+				if (count_bytes || (c == '\n')) {
+					--i;
+				}
+				putchar(c);
 			}
-			if (optind < argc - 1)
-				putchar('\n');
-			if (fp != stdin)
-				fclose(fp);
+			if (fclose_if_not_stdin(fp)) {
+				bb_simple_perror_msg(*argv);
+				retval = EXIT_FAILURE;
+			}
+			die_if_ferror_stdout();
+		} else {
+			retval = EXIT_FAILURE;
 		}
-		optind++;
-	}
+		fmt = header_fmt_str;
+	} while (*++argv);
 
-	return status;
+	fflush_stdout_and_exit(retval);
 }