Implemented head(1).

tried to mimic GNU behaviour.
author: John Beppu <beppu@lbox.org> 1999-12-10 07:42:50 +0000
committer: John Beppu <beppu@lbox.org> 1999-12-10 07:42:50 +0000
commit: 3157b1fba9ee8a558b04e9025da9f77e4256c0ea (patch)
tree: 27ea10d69773a06c8618132a2b76e7583db9da9c /coreutils/head.c
parent: a3e0d7928b0042dfe1be94da62b750664306b404 (diff)
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1 files changed, 106 insertions, 0 deletions
diff --git a/coreutils/head.c b/coreutils/head.c
new file mode 100644
index 000000000..930839de3
--- /dev/null
+++ b/coreutils/head.c
@@ -0,0 +1,106 @@
+/*
+ * Mini head implementation for busybox
+ *
+ *
+ * Copyright (C) 1999 by Lineo, inc.
+ * Written by John Beppu <beppu@line.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
+ *
+ */
+#include "internal.h"
+#include <errno.h>
+#include <stdio.h>
+const char head_usage[] =
+"Usage: head [OPTION]... [FILE]...\n"
+"Print first 10 lines of each FILE to standard output.\n"
+"With more than one FILE, precede each with a header giving the file name.\n"
+"With no FILE, or when FILE is -, read standard input.\n\n"
+"  -h   display this help and exit\n";
+int
+head(int len, FILE *src)
+{
+    int     i;
+    char    buffer[1024];
+    for (i = 0; i < len; i++) {
+        fgets(buffer, 1024, src);
+        if (feof(src)) { break; }
+        fputs(buffer, stdout);
+    }
+    return 0;
+}
+/* BusyBoxed head(1) */
+int
+head_main(int argc, char **argv)
+{
+    int     i = 1;
+    char    opt;
+    int     len = 10;
+    /* 1st option is potentially special */
+    if ((argv[1][0] == '-') && isDecimal(argv[1][1])) {
+        int tmplen = atoi(&argv[1][1]);
+        if (tmplen) { len = tmplen; }
+        i = 2;
+    }
+    /* parse argv[] */
+    for ( ; i < argc; i++) {
+        if (argv[i][0] == '-') {
+            opt = argv[i][1];
+            switch (opt) {
+                case 'h':
+                    usage(head_usage);
+                default:
+                    fprintf(stderr, "head: invalid option -- %c\n", opt);
+                    usage(head_usage);
+            }
+        } else {
+            break;
+        }
+    }
+    /* get rest of argv[] or stdin if nothing's left */
+    if (i >= argc) {
+        head(len, stdin);
+    } else {
+        int need_headers = ((argc - i) > 1);
+        for ( ; i < argc; i++) {
+            FILE *src;
+            src = fopen(argv[i], "r");
+            if (!src) {
+                fprintf(stderr,"head: %s: %s\n", argv[i], strerror(errno));
+            } else {
+                /* emulating GNU behaviour */
+                if (need_headers) { 
+                    fprintf(stdout, "==> %s <==\n", argv[i]);
+                }
+                head(len, src);
+                if (i < argc - 1) {
+                    fprintf(stdout, "\n");
+                }
+            }
+        }
+    }
+    exit(0);
+}
+/* $Id: head.c,v 1.1 1999/12/10 07:42:50 beppu Exp $ */
author	John Beppu <beppu@lbox.org>	1999-12-10 07:42:50 +0000
committer	John Beppu <beppu@lbox.org>	1999-12-10 07:42:50 +0000
commit	3157b1fba9ee8a558b04e9025da9f77e4256c0ea (patch)
tree	27ea10d69773a06c8618132a2b76e7583db9da9c /coreutils/head.c
parent	a3e0d7928b0042dfe1be94da62b750664306b404 (diff)
download	busybox-w32-3157b1fba9ee8a558b04e9025da9f77e4256c0ea.tar.gz busybox-w32-3157b1fba9ee8a558b04e9025da9f77e4256c0ea.tar.bz2 busybox-w32-3157b1fba9ee8a558b04e9025da9f77e4256c0ea.zip

diff --git a/coreutils/head.c b/coreutils/head.c new file mode 100644 index 000000000..930839de3 --- /dev/null +++ b/coreutils/head.c
@@ -0,0 +1,106 @@
	1	/*
	2	* Mini head implementation for busybox
	3	*
	4	*
	5	* Copyright (C) 1999 by Lineo, inc.
	6	* Written by John Beppu <beppu@line.com>
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License as published by
	10	* the Free Software Foundation; either version 2 of the License, or
	11	* (at your option) any later version.
	12	*
	13	* This program is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	16	* General Public License for more details.
	17	*
	18	* You should have received a copy of the GNU General Public License
	19	* along with this program; if not, write to the Free Software
	20	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	21	*
	22	*/
	23
	24	#include "internal.h"
	25	#include <errno.h>
	26	#include <stdio.h>
	27
	28	const char head_usage[] =
	29	"Usage: head [OPTION]... [FILE]...\n"
	30	"Print first 10 lines of each FILE to standard output.\n"
	31	"With more than one FILE, precede each with a header giving the file name.\n"
	32	"With no FILE, or when FILE is -, read standard input.\n\n"
	33	" -h display this help and exit\n";
	34
	35	int
	36	head(int len, FILE *src)
	37	{
	38	int i;
	39	char buffer[1024];
	40
	41	for (i = 0; i < len; i++) {
	42	fgets(buffer, 1024, src);
	43	if (feof(src)) { break; }
	44	fputs(buffer, stdout);
	45	}
	46	return 0;
	47	}
	48
	49	/* BusyBoxed head(1) */
	50	int
	51	head_main(int argc, char **argv)
	52	{
	53	int i = 1;
	54	char opt;
	55	int len = 10;
	56
	57	/* 1st option is potentially special */
	58	if ((argv[1][0] == '-') && isDecimal(argv[1][1])) {
	59	int tmplen = atoi(&argv[1][1]);
	60	if (tmplen) { len = tmplen; }
	61	i = 2;
	62	}
	63
	64	/* parse argv[] */
	65	for ( ; i < argc; i++) {
	66	if (argv[i][0] == '-') {
	67	opt = argv[i][1];
	68	switch (opt) {
	69	case 'h':
	70	usage(head_usage);
	71	default:
	72	fprintf(stderr, "head: invalid option -- %c\n", opt);
	73	usage(head_usage);
	74	}
	75	} else {
	76	break;
	77	}
	78	}
	79
	80	/* get rest of argv[] or stdin if nothing's left */
	81	if (i >= argc) {
	82	head(len, stdin);
	83
	84	} else {
	85	int need_headers = ((argc - i) > 1);
	86	for ( ; i < argc; i++) {
	87	FILE *src;
	88	src = fopen(argv[i], "r");
	89	if (!src) {
	90	fprintf(stderr,"head: %s: %s\n", argv[i], strerror(errno));
	91	} else {
	92	/* emulating GNU behaviour */
	93	if (need_headers) {
	94	fprintf(stdout, "==> %s <==\n", argv[i]);
	95	}
	96	head(len, src);
	97	if (i < argc - 1) {
	98	fprintf(stdout, "\n");
	99	}
	100	}
	101	}
	102	}
	103	exit(0);
	104	}
	105
	106	/* $Id: head.c,v 1.1 1999/12/10 07:42:50 beppu Exp $ */