xref: /titanic_41/usr/src/cmd/head/head.c (revision 7c478bd95313f5f23a4c958a745db2134aa03244)
1*7c478bd9Sstevel@tonic-gate /*
2*7c478bd9Sstevel@tonic-gate  * CDDL HEADER START
3*7c478bd9Sstevel@tonic-gate  *
4*7c478bd9Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
5*7c478bd9Sstevel@tonic-gate  * Common Development and Distribution License, Version 1.0 only
6*7c478bd9Sstevel@tonic-gate  * (the "License").  You may not use this file except in compliance
7*7c478bd9Sstevel@tonic-gate  * with the License.
8*7c478bd9Sstevel@tonic-gate  *
9*7c478bd9Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10*7c478bd9Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
11*7c478bd9Sstevel@tonic-gate  * See the License for the specific language governing permissions
12*7c478bd9Sstevel@tonic-gate  * and limitations under the License.
13*7c478bd9Sstevel@tonic-gate  *
14*7c478bd9Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
15*7c478bd9Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16*7c478bd9Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
17*7c478bd9Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
18*7c478bd9Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
19*7c478bd9Sstevel@tonic-gate  *
20*7c478bd9Sstevel@tonic-gate  * CDDL HEADER END
21*7c478bd9Sstevel@tonic-gate  */
22*7c478bd9Sstevel@tonic-gate /*
23*7c478bd9Sstevel@tonic-gate  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24*7c478bd9Sstevel@tonic-gate  * Use is subject to license terms.
25*7c478bd9Sstevel@tonic-gate  */
26*7c478bd9Sstevel@tonic-gate 
27*7c478bd9Sstevel@tonic-gate /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
28*7c478bd9Sstevel@tonic-gate /*	  All Rights Reserved  	*/
29*7c478bd9Sstevel@tonic-gate 
30*7c478bd9Sstevel@tonic-gate /*
31*7c478bd9Sstevel@tonic-gate  * University Copyright- Copyright (c) 1982, 1986, 1988
32*7c478bd9Sstevel@tonic-gate  * The Regents of the University of California
33*7c478bd9Sstevel@tonic-gate  * All Rights Reserved
34*7c478bd9Sstevel@tonic-gate  *
35*7c478bd9Sstevel@tonic-gate  * University Acknowledgment- Portions of this document are derived from
36*7c478bd9Sstevel@tonic-gate  * software developed by the University of California, Berkeley, and its
37*7c478bd9Sstevel@tonic-gate  * contributors.
38*7c478bd9Sstevel@tonic-gate  */
39*7c478bd9Sstevel@tonic-gate 
40*7c478bd9Sstevel@tonic-gate #pragma ident	"%Z%%M%	%I%	%E% SMI"
41*7c478bd9Sstevel@tonic-gate 
42*7c478bd9Sstevel@tonic-gate 
43*7c478bd9Sstevel@tonic-gate #include <stdio.h>
44*7c478bd9Sstevel@tonic-gate #include <stdlib.h>
45*7c478bd9Sstevel@tonic-gate #include <unistd.h>
46*7c478bd9Sstevel@tonic-gate #include <locale.h>
47*7c478bd9Sstevel@tonic-gate #include <string.h>
48*7c478bd9Sstevel@tonic-gate #include <ctype.h>
49*7c478bd9Sstevel@tonic-gate 
50*7c478bd9Sstevel@tonic-gate #define	DEF_LINE_COUNT	10
51*7c478bd9Sstevel@tonic-gate 
52*7c478bd9Sstevel@tonic-gate static	void	copyout(off_t);
53*7c478bd9Sstevel@tonic-gate static	void	Usage();
54*7c478bd9Sstevel@tonic-gate 
55*7c478bd9Sstevel@tonic-gate 
56*7c478bd9Sstevel@tonic-gate /*
57*7c478bd9Sstevel@tonic-gate  * head - give the first few lines of a stream or of each of a set of files
58*7c478bd9Sstevel@tonic-gate  *
59*7c478bd9Sstevel@tonic-gate  */
60*7c478bd9Sstevel@tonic-gate int
61*7c478bd9Sstevel@tonic-gate main(int argc, char **argv)
62*7c478bd9Sstevel@tonic-gate {
63*7c478bd9Sstevel@tonic-gate 	int	fileCount;
64*7c478bd9Sstevel@tonic-gate 	int	around = 0;
65*7c478bd9Sstevel@tonic-gate 	int	i;
66*7c478bd9Sstevel@tonic-gate 	int	opt;
67*7c478bd9Sstevel@tonic-gate 	off_t	linecnt	= DEF_LINE_COUNT;
68*7c478bd9Sstevel@tonic-gate 	int	error = 0;
69*7c478bd9Sstevel@tonic-gate 
70*7c478bd9Sstevel@tonic-gate 	(void) setlocale(LC_ALL, "");
71*7c478bd9Sstevel@tonic-gate #if !defined(TEXT_DOMAIN)	/* Should be defined by cc -D */
72*7c478bd9Sstevel@tonic-gate #define	TEXT_DOMAIN "SYS_TEST"	/* Use this only if it weren't */
73*7c478bd9Sstevel@tonic-gate #endif
74*7c478bd9Sstevel@tonic-gate 	(void) textdomain(TEXT_DOMAIN);
75*7c478bd9Sstevel@tonic-gate 
76*7c478bd9Sstevel@tonic-gate 	/* check for non-standard "-line-count" option */
77*7c478bd9Sstevel@tonic-gate 	for (i = 1; i < argc; i++) {
78*7c478bd9Sstevel@tonic-gate 		if (strcmp(argv[i], "--") == 0)
79*7c478bd9Sstevel@tonic-gate 			break;
80*7c478bd9Sstevel@tonic-gate 
81*7c478bd9Sstevel@tonic-gate 		if ((argv[i][0] == '-') && isdigit(argv[i][1])) {
82*7c478bd9Sstevel@tonic-gate 			if (strlen(&argv[i][1]) !=
83*7c478bd9Sstevel@tonic-gate 			    strspn(&argv[i][1], "0123456789")) {
84*7c478bd9Sstevel@tonic-gate 				(void) fprintf(stderr, gettext(
85*7c478bd9Sstevel@tonic-gate 				    "%s: Badly formed number\n"), argv[0]);
86*7c478bd9Sstevel@tonic-gate 				Usage();
87*7c478bd9Sstevel@tonic-gate 			}
88*7c478bd9Sstevel@tonic-gate 
89*7c478bd9Sstevel@tonic-gate 			linecnt = (off_t) strtoll(&argv[i][1], (char **)NULL,
90*7c478bd9Sstevel@tonic-gate 			    10);
91*7c478bd9Sstevel@tonic-gate 			while (i < argc) {
92*7c478bd9Sstevel@tonic-gate 				argv[i] = argv[i + 1];
93*7c478bd9Sstevel@tonic-gate 				i++;
94*7c478bd9Sstevel@tonic-gate 			}
95*7c478bd9Sstevel@tonic-gate 			argc--;
96*7c478bd9Sstevel@tonic-gate 		}
97*7c478bd9Sstevel@tonic-gate 	}
98*7c478bd9Sstevel@tonic-gate 
99*7c478bd9Sstevel@tonic-gate 	/* get options */
100*7c478bd9Sstevel@tonic-gate 	while ((opt = getopt(argc, argv, "n:")) != EOF) {
101*7c478bd9Sstevel@tonic-gate 		switch (opt) {
102*7c478bd9Sstevel@tonic-gate 		case 'n':
103*7c478bd9Sstevel@tonic-gate 			if ((strcmp(optarg, "--") == 0) || (optind > argc)) {
104*7c478bd9Sstevel@tonic-gate 				(void) fprintf(stderr, gettext(
105*7c478bd9Sstevel@tonic-gate 				    "%s: Missing -n argument\n"), argv[0]),
106*7c478bd9Sstevel@tonic-gate 				Usage();
107*7c478bd9Sstevel@tonic-gate 			}
108*7c478bd9Sstevel@tonic-gate 			linecnt = (off_t) strtoll(optarg, (char **)NULL, 10);
109*7c478bd9Sstevel@tonic-gate 			if (linecnt <= 0) {
110*7c478bd9Sstevel@tonic-gate 				(void) fprintf(stderr, gettext(
111*7c478bd9Sstevel@tonic-gate 				    "%s: Invalid \"-n %s\" option\n"),
112*7c478bd9Sstevel@tonic-gate 				    argv[0], optarg);
113*7c478bd9Sstevel@tonic-gate 				Usage();
114*7c478bd9Sstevel@tonic-gate 			}
115*7c478bd9Sstevel@tonic-gate 			break;
116*7c478bd9Sstevel@tonic-gate 
117*7c478bd9Sstevel@tonic-gate 		default:
118*7c478bd9Sstevel@tonic-gate 			Usage();
119*7c478bd9Sstevel@tonic-gate 		}
120*7c478bd9Sstevel@tonic-gate 	}
121*7c478bd9Sstevel@tonic-gate 
122*7c478bd9Sstevel@tonic-gate 	fileCount = argc - optind;
123*7c478bd9Sstevel@tonic-gate 
124*7c478bd9Sstevel@tonic-gate 	do {
125*7c478bd9Sstevel@tonic-gate 		if ((argv[optind] == NULL) && around)
126*7c478bd9Sstevel@tonic-gate 			break;
127*7c478bd9Sstevel@tonic-gate 
128*7c478bd9Sstevel@tonic-gate 		if (argv[optind] != NULL) {
129*7c478bd9Sstevel@tonic-gate 			(void) close(0);
130*7c478bd9Sstevel@tonic-gate 			if (freopen(argv[optind], "r", stdin) == NULL) {
131*7c478bd9Sstevel@tonic-gate 				perror(argv[optind]);
132*7c478bd9Sstevel@tonic-gate 				error = 1;
133*7c478bd9Sstevel@tonic-gate 				optind++;
134*7c478bd9Sstevel@tonic-gate 				continue;
135*7c478bd9Sstevel@tonic-gate 			}
136*7c478bd9Sstevel@tonic-gate 		}
137*7c478bd9Sstevel@tonic-gate 
138*7c478bd9Sstevel@tonic-gate 		if (around)
139*7c478bd9Sstevel@tonic-gate 			(void) putchar('\n');
140*7c478bd9Sstevel@tonic-gate 
141*7c478bd9Sstevel@tonic-gate 		if (fileCount > 1)
142*7c478bd9Sstevel@tonic-gate 			(void) printf("==> %s <==\n", argv[optind]);
143*7c478bd9Sstevel@tonic-gate 
144*7c478bd9Sstevel@tonic-gate 		if (argv[optind] != NULL)
145*7c478bd9Sstevel@tonic-gate 			optind++;
146*7c478bd9Sstevel@tonic-gate 
147*7c478bd9Sstevel@tonic-gate 		copyout(linecnt);
148*7c478bd9Sstevel@tonic-gate 		(void) fflush(stdout);
149*7c478bd9Sstevel@tonic-gate 		around++;
150*7c478bd9Sstevel@tonic-gate 
151*7c478bd9Sstevel@tonic-gate 	} while (argv[optind] != NULL);
152*7c478bd9Sstevel@tonic-gate 
153*7c478bd9Sstevel@tonic-gate 	return (error);
154*7c478bd9Sstevel@tonic-gate }
155*7c478bd9Sstevel@tonic-gate 
156*7c478bd9Sstevel@tonic-gate static void
157*7c478bd9Sstevel@tonic-gate copyout(cnt)
158*7c478bd9Sstevel@tonic-gate 	register off_t cnt;
159*7c478bd9Sstevel@tonic-gate {
160*7c478bd9Sstevel@tonic-gate 	char lbuf[BUFSIZ];
161*7c478bd9Sstevel@tonic-gate 	size_t len;
162*7c478bd9Sstevel@tonic-gate 
163*7c478bd9Sstevel@tonic-gate 	while (cnt > 0 && fgets(lbuf, sizeof (lbuf), stdin) != 0) {
164*7c478bd9Sstevel@tonic-gate 		(void) printf("%s", lbuf);
165*7c478bd9Sstevel@tonic-gate 		/* only count as a line if buffer read ends with newline */
166*7c478bd9Sstevel@tonic-gate 		if ((len = strlen(lbuf)) > 0) {
167*7c478bd9Sstevel@tonic-gate 			if (lbuf[len - 1] == '\n') {
168*7c478bd9Sstevel@tonic-gate 			(void) fflush(stdout);
169*7c478bd9Sstevel@tonic-gate 			cnt--;
170*7c478bd9Sstevel@tonic-gate 			}
171*7c478bd9Sstevel@tonic-gate 		}
172*7c478bd9Sstevel@tonic-gate 	}
173*7c478bd9Sstevel@tonic-gate }
174*7c478bd9Sstevel@tonic-gate 
175*7c478bd9Sstevel@tonic-gate static void
176*7c478bd9Sstevel@tonic-gate Usage()
177*7c478bd9Sstevel@tonic-gate {
178*7c478bd9Sstevel@tonic-gate 	(void) printf(gettext("usage: head [-n #] [-#] [filename...]\n"));
179*7c478bd9Sstevel@tonic-gate 	exit(1);
180*7c478bd9Sstevel@tonic-gate }
181