xref: /onnv-gate/usr/src/cmd/head/head.c (revision 0:68f95e015346)
1*0Sstevel@tonic-gate /*
2*0Sstevel@tonic-gate  * CDDL HEADER START
3*0Sstevel@tonic-gate  *
4*0Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
5*0Sstevel@tonic-gate  * Common Development and Distribution License, Version 1.0 only
6*0Sstevel@tonic-gate  * (the "License").  You may not use this file except in compliance
7*0Sstevel@tonic-gate  * with the License.
8*0Sstevel@tonic-gate  *
9*0Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10*0Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
11*0Sstevel@tonic-gate  * See the License for the specific language governing permissions
12*0Sstevel@tonic-gate  * and limitations under the License.
13*0Sstevel@tonic-gate  *
14*0Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
15*0Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16*0Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
17*0Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
18*0Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
19*0Sstevel@tonic-gate  *
20*0Sstevel@tonic-gate  * CDDL HEADER END
21*0Sstevel@tonic-gate  */
22*0Sstevel@tonic-gate /*
23*0Sstevel@tonic-gate  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24*0Sstevel@tonic-gate  * Use is subject to license terms.
25*0Sstevel@tonic-gate  */
26*0Sstevel@tonic-gate 
27*0Sstevel@tonic-gate /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
28*0Sstevel@tonic-gate /*	  All Rights Reserved  	*/
29*0Sstevel@tonic-gate 
30*0Sstevel@tonic-gate /*
31*0Sstevel@tonic-gate  * University Copyright- Copyright (c) 1982, 1986, 1988
32*0Sstevel@tonic-gate  * The Regents of the University of California
33*0Sstevel@tonic-gate  * All Rights Reserved
34*0Sstevel@tonic-gate  *
35*0Sstevel@tonic-gate  * University Acknowledgment- Portions of this document are derived from
36*0Sstevel@tonic-gate  * software developed by the University of California, Berkeley, and its
37*0Sstevel@tonic-gate  * contributors.
38*0Sstevel@tonic-gate  */
39*0Sstevel@tonic-gate 
40*0Sstevel@tonic-gate #pragma ident	"%Z%%M%	%I%	%E% SMI"
41*0Sstevel@tonic-gate 
42*0Sstevel@tonic-gate 
43*0Sstevel@tonic-gate #include <stdio.h>
44*0Sstevel@tonic-gate #include <stdlib.h>
45*0Sstevel@tonic-gate #include <unistd.h>
46*0Sstevel@tonic-gate #include <locale.h>
47*0Sstevel@tonic-gate #include <string.h>
48*0Sstevel@tonic-gate #include <ctype.h>
49*0Sstevel@tonic-gate 
50*0Sstevel@tonic-gate #define	DEF_LINE_COUNT	10
51*0Sstevel@tonic-gate 
52*0Sstevel@tonic-gate static	void	copyout(off_t);
53*0Sstevel@tonic-gate static	void	Usage();
54*0Sstevel@tonic-gate 
55*0Sstevel@tonic-gate 
56*0Sstevel@tonic-gate /*
57*0Sstevel@tonic-gate  * head - give the first few lines of a stream or of each of a set of files
58*0Sstevel@tonic-gate  *
59*0Sstevel@tonic-gate  */
60*0Sstevel@tonic-gate int
main(int argc,char ** argv)61*0Sstevel@tonic-gate main(int argc, char **argv)
62*0Sstevel@tonic-gate {
63*0Sstevel@tonic-gate 	int	fileCount;
64*0Sstevel@tonic-gate 	int	around = 0;
65*0Sstevel@tonic-gate 	int	i;
66*0Sstevel@tonic-gate 	int	opt;
67*0Sstevel@tonic-gate 	off_t	linecnt	= DEF_LINE_COUNT;
68*0Sstevel@tonic-gate 	int	error = 0;
69*0Sstevel@tonic-gate 
70*0Sstevel@tonic-gate 	(void) setlocale(LC_ALL, "");
71*0Sstevel@tonic-gate #if !defined(TEXT_DOMAIN)	/* Should be defined by cc -D */
72*0Sstevel@tonic-gate #define	TEXT_DOMAIN "SYS_TEST"	/* Use this only if it weren't */
73*0Sstevel@tonic-gate #endif
74*0Sstevel@tonic-gate 	(void) textdomain(TEXT_DOMAIN);
75*0Sstevel@tonic-gate 
76*0Sstevel@tonic-gate 	/* check for non-standard "-line-count" option */
77*0Sstevel@tonic-gate 	for (i = 1; i < argc; i++) {
78*0Sstevel@tonic-gate 		if (strcmp(argv[i], "--") == 0)
79*0Sstevel@tonic-gate 			break;
80*0Sstevel@tonic-gate 
81*0Sstevel@tonic-gate 		if ((argv[i][0] == '-') && isdigit(argv[i][1])) {
82*0Sstevel@tonic-gate 			if (strlen(&argv[i][1]) !=
83*0Sstevel@tonic-gate 			    strspn(&argv[i][1], "0123456789")) {
84*0Sstevel@tonic-gate 				(void) fprintf(stderr, gettext(
85*0Sstevel@tonic-gate 				    "%s: Badly formed number\n"), argv[0]);
86*0Sstevel@tonic-gate 				Usage();
87*0Sstevel@tonic-gate 			}
88*0Sstevel@tonic-gate 
89*0Sstevel@tonic-gate 			linecnt = (off_t) strtoll(&argv[i][1], (char **)NULL,
90*0Sstevel@tonic-gate 			    10);
91*0Sstevel@tonic-gate 			while (i < argc) {
92*0Sstevel@tonic-gate 				argv[i] = argv[i + 1];
93*0Sstevel@tonic-gate 				i++;
94*0Sstevel@tonic-gate 			}
95*0Sstevel@tonic-gate 			argc--;
96*0Sstevel@tonic-gate 		}
97*0Sstevel@tonic-gate 	}
98*0Sstevel@tonic-gate 
99*0Sstevel@tonic-gate 	/* get options */
100*0Sstevel@tonic-gate 	while ((opt = getopt(argc, argv, "n:")) != EOF) {
101*0Sstevel@tonic-gate 		switch (opt) {
102*0Sstevel@tonic-gate 		case 'n':
103*0Sstevel@tonic-gate 			if ((strcmp(optarg, "--") == 0) || (optind > argc)) {
104*0Sstevel@tonic-gate 				(void) fprintf(stderr, gettext(
105*0Sstevel@tonic-gate 				    "%s: Missing -n argument\n"), argv[0]),
106*0Sstevel@tonic-gate 				Usage();
107*0Sstevel@tonic-gate 			}
108*0Sstevel@tonic-gate 			linecnt = (off_t) strtoll(optarg, (char **)NULL, 10);
109*0Sstevel@tonic-gate 			if (linecnt <= 0) {
110*0Sstevel@tonic-gate 				(void) fprintf(stderr, gettext(
111*0Sstevel@tonic-gate 				    "%s: Invalid \"-n %s\" option\n"),
112*0Sstevel@tonic-gate 				    argv[0], optarg);
113*0Sstevel@tonic-gate 				Usage();
114*0Sstevel@tonic-gate 			}
115*0Sstevel@tonic-gate 			break;
116*0Sstevel@tonic-gate 
117*0Sstevel@tonic-gate 		default:
118*0Sstevel@tonic-gate 			Usage();
119*0Sstevel@tonic-gate 		}
120*0Sstevel@tonic-gate 	}
121*0Sstevel@tonic-gate 
122*0Sstevel@tonic-gate 	fileCount = argc - optind;
123*0Sstevel@tonic-gate 
124*0Sstevel@tonic-gate 	do {
125*0Sstevel@tonic-gate 		if ((argv[optind] == NULL) && around)
126*0Sstevel@tonic-gate 			break;
127*0Sstevel@tonic-gate 
128*0Sstevel@tonic-gate 		if (argv[optind] != NULL) {
129*0Sstevel@tonic-gate 			(void) close(0);
130*0Sstevel@tonic-gate 			if (freopen(argv[optind], "r", stdin) == NULL) {
131*0Sstevel@tonic-gate 				perror(argv[optind]);
132*0Sstevel@tonic-gate 				error = 1;
133*0Sstevel@tonic-gate 				optind++;
134*0Sstevel@tonic-gate 				continue;
135*0Sstevel@tonic-gate 			}
136*0Sstevel@tonic-gate 		}
137*0Sstevel@tonic-gate 
138*0Sstevel@tonic-gate 		if (around)
139*0Sstevel@tonic-gate 			(void) putchar('\n');
140*0Sstevel@tonic-gate 
141*0Sstevel@tonic-gate 		if (fileCount > 1)
142*0Sstevel@tonic-gate 			(void) printf("==> %s <==\n", argv[optind]);
143*0Sstevel@tonic-gate 
144*0Sstevel@tonic-gate 		if (argv[optind] != NULL)
145*0Sstevel@tonic-gate 			optind++;
146*0Sstevel@tonic-gate 
147*0Sstevel@tonic-gate 		copyout(linecnt);
148*0Sstevel@tonic-gate 		(void) fflush(stdout);
149*0Sstevel@tonic-gate 		around++;
150*0Sstevel@tonic-gate 
151*0Sstevel@tonic-gate 	} while (argv[optind] != NULL);
152*0Sstevel@tonic-gate 
153*0Sstevel@tonic-gate 	return (error);
154*0Sstevel@tonic-gate }
155*0Sstevel@tonic-gate 
156*0Sstevel@tonic-gate static void
copyout(cnt)157*0Sstevel@tonic-gate copyout(cnt)
158*0Sstevel@tonic-gate 	register off_t cnt;
159*0Sstevel@tonic-gate {
160*0Sstevel@tonic-gate 	char lbuf[BUFSIZ];
161*0Sstevel@tonic-gate 	size_t len;
162*0Sstevel@tonic-gate 
163*0Sstevel@tonic-gate 	while (cnt > 0 && fgets(lbuf, sizeof (lbuf), stdin) != 0) {
164*0Sstevel@tonic-gate 		(void) printf("%s", lbuf);
165*0Sstevel@tonic-gate 		/* only count as a line if buffer read ends with newline */
166*0Sstevel@tonic-gate 		if ((len = strlen(lbuf)) > 0) {
167*0Sstevel@tonic-gate 			if (lbuf[len - 1] == '\n') {
168*0Sstevel@tonic-gate 			(void) fflush(stdout);
169*0Sstevel@tonic-gate 			cnt--;
170*0Sstevel@tonic-gate 			}
171*0Sstevel@tonic-gate 		}
172*0Sstevel@tonic-gate 	}
173*0Sstevel@tonic-gate }
174*0Sstevel@tonic-gate 
175*0Sstevel@tonic-gate static void
Usage()176*0Sstevel@tonic-gate Usage()
177*0Sstevel@tonic-gate {
178*0Sstevel@tonic-gate 	(void) printf(gettext("usage: head [-n #] [-#] [filename...]\n"));
179*0Sstevel@tonic-gate 	exit(1);
180*0Sstevel@tonic-gate }
181