1*3ac07874Smrg /* $NetBSD: head.c,v 1.7 1997/10/18 13:15:40 mrg Exp $ */ 29d225a17Stls 361f28255Scgd /* 4*3ac07874Smrg * Copyright (c) 1980, 1987, 1992, 1993 5*3ac07874Smrg * The Regents of the University of California. All rights reserved. 661f28255Scgd * 761f28255Scgd * Redistribution and use in source and binary forms, with or without 861f28255Scgd * modification, are permitted provided that the following conditions 961f28255Scgd * are met: 1061f28255Scgd * 1. Redistributions of source code must retain the above copyright 1161f28255Scgd * notice, this list of conditions and the following disclaimer. 1261f28255Scgd * 2. Redistributions in binary form must reproduce the above copyright 1361f28255Scgd * notice, this list of conditions and the following disclaimer in the 1461f28255Scgd * documentation and/or other materials provided with the distribution. 1561f28255Scgd * 3. All advertising materials mentioning features or use of this software 1661f28255Scgd * must display the following acknowledgement: 1761f28255Scgd * This product includes software developed by the University of 1861f28255Scgd * California, Berkeley and its contributors. 1961f28255Scgd * 4. Neither the name of the University nor the names of its contributors 2061f28255Scgd * may be used to endorse or promote products derived from this software 2161f28255Scgd * without specific prior written permission. 2261f28255Scgd * 2361f28255Scgd * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 2461f28255Scgd * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 2561f28255Scgd * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 2661f28255Scgd * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 2761f28255Scgd * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 2861f28255Scgd * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 2961f28255Scgd * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 3061f28255Scgd * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 3161f28255Scgd * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 3261f28255Scgd * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 3361f28255Scgd * SUCH DAMAGE. 3461f28255Scgd */ 3561f28255Scgd 36*3ac07874Smrg #include <sys/cdefs.h> 3761f28255Scgd #ifndef lint 38*3ac07874Smrg __COPYRIGHT("@(#) Copyright (c) 1980, 1987, 1992, 1993\n\ 39*3ac07874Smrg The Regents of the University of California. All rights reserved.\n"); 4061f28255Scgd #endif /* not lint */ 4161f28255Scgd 4261f28255Scgd #ifndef lint 43*3ac07874Smrg #if 0 44*3ac07874Smrg static char sccsid[] = "@(#)head.c 8.2 (Berkeley) 5/4/95"; 45*3ac07874Smrg #else 46*3ac07874Smrg __RCSID("$NetBSD: head.c,v 1.7 1997/10/18 13:15:40 mrg Exp $"); 47*3ac07874Smrg #endif 4861f28255Scgd #endif /* not lint */ 4961f28255Scgd 50*3ac07874Smrg #include <sys/types.h> 51*3ac07874Smrg 52*3ac07874Smrg #include <ctype.h> 53*3ac07874Smrg #include <errno.h> 5461f28255Scgd #include <stdio.h> 55aab7593aSjtc #include <stdlib.h> 56*3ac07874Smrg #include <string.h> 572ddbb97fSjtc #include <unistd.h> 58aab7593aSjtc 5961f28255Scgd /* 6061f28255Scgd * head - give the first few lines of a stream or of each of a set of files 6161f28255Scgd * 6261f28255Scgd * Bill Joy UCB August 24, 1977 6361f28255Scgd */ 6461f28255Scgd 65*3ac07874Smrg void err __P((int, const char *, ...)); 66*3ac07874Smrg void head __P((FILE *, int)); 67*3ac07874Smrg void obsolete __P((char *[])); 68*3ac07874Smrg void usage __P((void)); 69*3ac07874Smrg int main __P((int, char *[])); 70*3ac07874Smrg 71*3ac07874Smrg int eval; 72*3ac07874Smrg 73f7c6bf57Sjtc int 7461f28255Scgd main(argc, argv) 7561f28255Scgd int argc; 76*3ac07874Smrg char *argv[]; 7761f28255Scgd { 78*3ac07874Smrg register int ch; 79*3ac07874Smrg FILE *fp; 80*3ac07874Smrg int first, linecnt; 81*3ac07874Smrg char *ep; 8261f28255Scgd 83*3ac07874Smrg obsolete(argv); 84*3ac07874Smrg linecnt = 10; 85aab7593aSjtc while ((ch = getopt(argc, argv, "n:")) != EOF) 86aab7593aSjtc switch(ch) { 87aab7593aSjtc case 'n': 88*3ac07874Smrg linecnt = strtol(optarg, &ep, 10); 89*3ac07874Smrg if (*ep || linecnt <= 0) 90*3ac07874Smrg err(1, "illegal line count -- %s", optarg); 91aab7593aSjtc break; 92aab7593aSjtc 93*3ac07874Smrg case '?': 94aab7593aSjtc default: 95aab7593aSjtc usage(); 96aab7593aSjtc } 97*3ac07874Smrg argc -= optind; 98*3ac07874Smrg argv += optind; 99aab7593aSjtc 100*3ac07874Smrg if (*argv) 101*3ac07874Smrg for (first = 1; *argv; ++argv) { 102*3ac07874Smrg if ((fp = fopen(*argv, "r")) == NULL) { 103*3ac07874Smrg err(0, "%s: %s", *argv, strerror(errno)); 104*3ac07874Smrg continue; 10561f28255Scgd } 10661f28255Scgd if (argc > 1) { 107*3ac07874Smrg (void)printf("%s==> %s <==\n", 108*3ac07874Smrg first ? "" : "\n", *argv); 109*3ac07874Smrg first = 0; 11061f28255Scgd } 111*3ac07874Smrg head(fp, linecnt); 112*3ac07874Smrg (void)fclose(fp); 11361f28255Scgd } 114*3ac07874Smrg else 115*3ac07874Smrg head(stdin, linecnt); 116*3ac07874Smrg exit(eval); 117*3ac07874Smrg } 118*3ac07874Smrg 119*3ac07874Smrg void 120*3ac07874Smrg head(fp, cnt) 121*3ac07874Smrg FILE *fp; 122*3ac07874Smrg register int cnt; 123*3ac07874Smrg { 124*3ac07874Smrg register int ch; 125*3ac07874Smrg 126*3ac07874Smrg while (cnt--) 127*3ac07874Smrg while ((ch = getc(fp)) != EOF) { 128*3ac07874Smrg if (putchar(ch) == EOF) 129*3ac07874Smrg err(1, "stdout: %s", strerror(errno)); 130*3ac07874Smrg if (ch == '\n') 13161f28255Scgd break; 13261f28255Scgd } 13361f28255Scgd } 134aab7593aSjtc 135*3ac07874Smrg void 136*3ac07874Smrg obsolete(argv) 137*3ac07874Smrg char *argv[]; 138*3ac07874Smrg { 139*3ac07874Smrg char *ap; 140aab7593aSjtc 141*3ac07874Smrg while ((ap = *++argv)) { 142*3ac07874Smrg /* Return if "--" or not "-[0-9]*". */ 143*3ac07874Smrg if (ap[0] != '-' || ap[1] == '-' || !isdigit(ap[1])) 144*3ac07874Smrg return; 145*3ac07874Smrg if ((ap = malloc(strlen(*argv) + 2)) == NULL) 146*3ac07874Smrg err(1, "%s", strerror(errno)); 147*3ac07874Smrg ap[0] = '-'; 148*3ac07874Smrg ap[1] = 'n'; 149*3ac07874Smrg (void)strcpy(ap + 2, *argv + 1); 150*3ac07874Smrg *argv = ap; 151*3ac07874Smrg } 152*3ac07874Smrg } 153*3ac07874Smrg 154*3ac07874Smrg void 155aab7593aSjtc usage() 156aab7593aSjtc { 157*3ac07874Smrg (void)fputs("usage: head [-n lines] [file ...]\n", stderr); 158aab7593aSjtc exit(1); 159aab7593aSjtc } 160