11590Srgrimes/* 21590Srgrimes * Copyright (c) 1980, 1987, 1992, 1993 31590Srgrimes * The Regents of the University of California. All rights reserved. 41590Srgrimes * 51590Srgrimes * Redistribution and use in source and binary forms, with or without 61590Srgrimes * modification, are permitted provided that the following conditions 71590Srgrimes * are met: 81590Srgrimes * 1. Redistributions of source code must retain the above copyright 91590Srgrimes * notice, this list of conditions and the following disclaimer. 101590Srgrimes * 2. Redistributions in binary form must reproduce the above copyright 111590Srgrimes * notice, this list of conditions and the following disclaimer in the 121590Srgrimes * documentation and/or other materials provided with the distribution. 131590Srgrimes * 4. Neither the name of the University nor the names of its contributors 141590Srgrimes * may be used to endorse or promote products derived from this software 151590Srgrimes * without specific prior written permission. 161590Srgrimes * 171590Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 181590Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 191590Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 201590Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 211590Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 221590Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 231590Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 241590Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 251590Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 261590Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 271590Srgrimes * SUCH DAMAGE. 281590Srgrimes */ 291590Srgrimes 301590Srgrimes#ifndef lint 3127314Scharnierstatic const char copyright[] = 321590Srgrimes"@(#) Copyright (c) 1980, 1987, 1992, 1993\n\ 331590Srgrimes The Regents of the University of California. All rights reserved.\n"; 341590Srgrimes#endif /* not lint */ 351590Srgrimes 361590Srgrimes#ifndef lint 3727314Scharnier#if 0 3823693Speterstatic char sccsid[] = "@(#)head.c 8.2 (Berkeley) 5/4/95"; 3927314Scharnier#endif 401590Srgrimes#endif /* not lint */ 4199112Sobrien#include <sys/cdefs.h> 4299112Sobrien__FBSDID("$FreeBSD: releng/10.3/usr.bin/head/head.c 216370 2010-12-11 08:32:16Z joel $"); 431590Srgrimes 441590Srgrimes#include <sys/types.h> 4523693Speter 4623693Speter#include <ctype.h> 4727314Scharnier#include <err.h> 48165940Sbrooks#include <inttypes.h> 4923693Speter#include <stdio.h> 501590Srgrimes#include <stdlib.h> 511590Srgrimes#include <string.h> 5223693Speter#include <unistd.h> 531590Srgrimes 541590Srgrimes/* 551590Srgrimes * head - give the first few lines of a stream or of each of a set of files 561590Srgrimes * 571590Srgrimes * Bill Joy UCB August 24, 1977 581590Srgrimes */ 591590Srgrimes 6093441Sdwmalonestatic void head(FILE *, int); 61165940Sbrooksstatic void head_bytes(FILE *, off_t); 6293441Sdwmalonestatic void obsolete(char *[]); 6393441Sdwmalonestatic void usage(void); 641590Srgrimes 651590Srgrimesint 6695652Smarkmmain(int argc, char *argv[]) 671590Srgrimes{ 6893441Sdwmalone int ch; 691590Srgrimes FILE *fp; 70165940Sbrooks int first, linecnt = -1, eval = 0; 71165940Sbrooks off_t bytecnt = -1; 721590Srgrimes char *ep; 731590Srgrimes 741590Srgrimes obsolete(argv); 7524665Salex while ((ch = getopt(argc, argv, "n:c:")) != -1) 761590Srgrimes switch(ch) { 7724665Salex case 'c': 78165940Sbrooks bytecnt = strtoimax(optarg, &ep, 10); 7924665Salex if (*ep || bytecnt <= 0) 8027314Scharnier errx(1, "illegal byte count -- %s", optarg); 8124665Salex break; 821590Srgrimes case 'n': 831590Srgrimes linecnt = strtol(optarg, &ep, 10); 841590Srgrimes if (*ep || linecnt <= 0) 8527314Scharnier errx(1, "illegal line count -- %s", optarg); 861590Srgrimes break; 871590Srgrimes case '?': 881590Srgrimes default: 891590Srgrimes usage(); 901590Srgrimes } 911590Srgrimes argc -= optind; 921590Srgrimes argv += optind; 931590Srgrimes 9424665Salex if (linecnt != -1 && bytecnt != -1) 9527314Scharnier errx(1, "can't combine line and byte counts"); 9624665Salex if (linecnt == -1 ) 9724665Salex linecnt = 10; 9824665Salex if (*argv) { 991590Srgrimes for (first = 1; *argv; ++argv) { 1001590Srgrimes if ((fp = fopen(*argv, "r")) == NULL) { 10127314Scharnier warn("%s", *argv); 10227328Scharnier eval = 1; 1031590Srgrimes continue; 1041590Srgrimes } 1051590Srgrimes if (argc > 1) { 1061590Srgrimes (void)printf("%s==> %s <==\n", 1071590Srgrimes first ? "" : "\n", *argv); 1081590Srgrimes first = 0; 1091590Srgrimes } 11024665Salex if (bytecnt == -1) 11124665Salex head(fp, linecnt); 11224665Salex else 11324665Salex head_bytes(fp, bytecnt); 1141590Srgrimes (void)fclose(fp); 1151590Srgrimes } 11685859Salfred } else if (bytecnt == -1) 11724665Salex head(stdin, linecnt); 1181590Srgrimes else 11924665Salex head_bytes(stdin, bytecnt); 12024665Salex 1211590Srgrimes exit(eval); 1221590Srgrimes} 1231590Srgrimes 12493441Sdwmalonestatic void 12595652Smarkmhead(FILE *fp, int cnt) 1261590Srgrimes{ 12785861Salfred char *cp; 12893441Sdwmalone size_t error, readlen; 1291590Srgrimes 13085861Salfred while (cnt && (cp = fgetln(fp, &readlen)) != NULL) { 13185861Salfred error = fwrite(cp, sizeof(char), readlen, stdout); 13285861Salfred if (error != readlen) 13385861Salfred err(1, "stdout"); 13485861Salfred cnt--; 13585861Salfred } 1361590Srgrimes} 1371590Srgrimes 13893441Sdwmalonestatic void 139165940Sbrookshead_bytes(FILE *fp, off_t cnt) 14024665Salex{ 14124665Salex char buf[4096]; 14293441Sdwmalone size_t readlen; 14324665Salex 14424665Salex while (cnt) { 145165955Sbrooks if ((uintmax_t)cnt < sizeof(buf)) 14624665Salex readlen = cnt; 14724665Salex else 14824665Salex readlen = sizeof(buf); 14924665Salex readlen = fread(buf, sizeof(char), readlen, fp); 15040114Sdes if (readlen == 0) 15124665Salex break; 15224665Salex if (fwrite(buf, sizeof(char), readlen, stdout) != readlen) 15327314Scharnier err(1, "stdout"); 15424665Salex cnt -= readlen; 15524665Salex } 15624665Salex} 15724665Salex 15893441Sdwmalonestatic void 15995652Smarkmobsolete(char *argv[]) 1601590Srgrimes{ 1611590Srgrimes char *ap; 1621590Srgrimes 16324665Salex while ((ap = *++argv)) { 1641590Srgrimes /* Return if "--" or not "-[0-9]*". */ 1651590Srgrimes if (ap[0] != '-' || ap[1] == '-' || !isdigit(ap[1])) 1661590Srgrimes return; 1671590Srgrimes if ((ap = malloc(strlen(*argv) + 2)) == NULL) 16827314Scharnier err(1, NULL); 1691590Srgrimes ap[0] = '-'; 1701590Srgrimes ap[1] = 'n'; 1711590Srgrimes (void)strcpy(ap + 2, *argv + 1); 1721590Srgrimes *argv = ap; 1731590Srgrimes } 1741590Srgrimes} 1751590Srgrimes 17693441Sdwmalonestatic void 17795652Smarkmusage(void) 1781590Srgrimes{ 17985859Salfred 18089767Sdwmalone (void)fprintf(stderr, "usage: head [-n lines | -c bytes] [file ...]\n"); 1811590Srgrimes exit(1); 1821590Srgrimes} 183