161f28255Scgd /* 261f28255Scgd * Copyright (c) 1980, 1987 Regents of the University of California. 361f28255Scgd * All rights reserved. 461f28255Scgd * 561f28255Scgd * Redistribution and use in source and binary forms, with or without 661f28255Scgd * modification, are permitted provided that the following conditions 761f28255Scgd * are met: 861f28255Scgd * 1. Redistributions of source code must retain the above copyright 961f28255Scgd * notice, this list of conditions and the following disclaimer. 1061f28255Scgd * 2. Redistributions in binary form must reproduce the above copyright 1161f28255Scgd * notice, this list of conditions and the following disclaimer in the 1261f28255Scgd * documentation and/or other materials provided with the distribution. 1361f28255Scgd * 3. All advertising materials mentioning features or use of this software 1461f28255Scgd * must display the following acknowledgement: 1561f28255Scgd * This product includes software developed by the University of 1661f28255Scgd * California, Berkeley and its contributors. 1761f28255Scgd * 4. Neither the name of the University nor the names of its contributors 1861f28255Scgd * may be used to endorse or promote products derived from this software 1961f28255Scgd * without specific prior written permission. 2061f28255Scgd * 2161f28255Scgd * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 2261f28255Scgd * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 2361f28255Scgd * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 2461f28255Scgd * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 2561f28255Scgd * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 2661f28255Scgd * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 2761f28255Scgd * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 2861f28255Scgd * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 2961f28255Scgd * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 3061f28255Scgd * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 3161f28255Scgd * SUCH DAMAGE. 3261f28255Scgd */ 3361f28255Scgd 3461f28255Scgd #ifndef lint 3561f28255Scgd char copyright[] = 3661f28255Scgd "@(#) Copyright (c) 1980, 1987 Regents of the University of California.\n\ 3761f28255Scgd All rights reserved.\n"; 3861f28255Scgd #endif /* not lint */ 3961f28255Scgd 4061f28255Scgd #ifndef lint 41e9d867efSmycroft /*static char sccsid[] = "from: @(#)head.c 5.5 (Berkeley) 6/1/90";*/ 42*f7c6bf57Sjtc static char rcsid[] = "$Id: head.c,v 1.4 1993/08/27 22:30:27 jtc Exp $"; 4361f28255Scgd #endif /* not lint */ 4461f28255Scgd 4561f28255Scgd #include <stdio.h> 46aab7593aSjtc #include <stdlib.h> 4761f28255Scgd #include <ctype.h> 48aab7593aSjtc 49aab7593aSjtc static void usage (); 50aab7593aSjtc 5161f28255Scgd /* 5261f28255Scgd * head - give the first few lines of a stream or of each of a set of files 5361f28255Scgd * 5461f28255Scgd * Bill Joy UCB August 24, 1977 5561f28255Scgd */ 5661f28255Scgd 57*f7c6bf57Sjtc int 5861f28255Scgd main(argc, argv) 5961f28255Scgd int argc; 6061f28255Scgd char **argv; 6161f28255Scgd { 6261f28255Scgd register int ch, cnt; 6361f28255Scgd int firsttime, linecnt = 10; 6461f28255Scgd 65aab7593aSjtc /* handle obsolete -number syntax */ 66aab7593aSjtc if (argc > 1 && argv[1][0] == '-' && isdigit(argv[1][1])) { 6761f28255Scgd if ((linecnt = atoi(argv[1] + 1)) < 0) { 68aab7593aSjtc usage (); 6961f28255Scgd } 70aab7593aSjtc argc--; argv++; 7161f28255Scgd } 72aab7593aSjtc 73aab7593aSjtc while ((ch = getopt (argc, argv, "n:")) != EOF) 74aab7593aSjtc switch (ch) { 75aab7593aSjtc case 'n': 76aab7593aSjtc if ((linecnt = atoi(optarg)) < 0) 77aab7593aSjtc usage (); 78aab7593aSjtc break; 79aab7593aSjtc 80aab7593aSjtc default: 81aab7593aSjtc usage(); 82aab7593aSjtc } 83aab7593aSjtc argc -= optind, argv += optind; 84aab7593aSjtc 8561f28255Scgd /* setlinebuf(stdout); */ 86aab7593aSjtc for (firsttime = 1; ; firsttime = 0) { 8761f28255Scgd if (!*argv) { 8861f28255Scgd if (!firsttime) 8961f28255Scgd exit(0); 9061f28255Scgd } 9161f28255Scgd else { 9261f28255Scgd if (!freopen(*argv, "r", stdin)) { 9361f28255Scgd fprintf(stderr, "head: can't read %s.\n", *argv); 9461f28255Scgd exit(1); 9561f28255Scgd } 9661f28255Scgd if (argc > 1) { 9761f28255Scgd if (!firsttime) 9861f28255Scgd putchar('\n'); 9961f28255Scgd printf("==> %s <==\n", *argv); 10061f28255Scgd } 10161f28255Scgd ++argv; 10261f28255Scgd } 10361f28255Scgd for (cnt = linecnt; cnt; --cnt) 10461f28255Scgd while ((ch = getchar()) != EOF) 10561f28255Scgd if (putchar(ch) == '\n') 10661f28255Scgd break; 10761f28255Scgd } 10861f28255Scgd /*NOTREACHED*/ 10961f28255Scgd } 110aab7593aSjtc 111aab7593aSjtc 112aab7593aSjtc static void 113aab7593aSjtc usage () 114aab7593aSjtc { 115aab7593aSjtc fputs("usage: head [-n line_count] [file ...]\n", stderr); 116aab7593aSjtc exit(1); 117aab7593aSjtc } 118aab7593aSjtc 119