19b50d902SRodney W. Grimes /* 29b50d902SRodney W. Grimes * Copyright (c) 1980, 1987, 1992, 1993 39b50d902SRodney W. Grimes * The Regents of the University of California. All rights reserved. 49b50d902SRodney W. Grimes * 59b50d902SRodney W. Grimes * Redistribution and use in source and binary forms, with or without 69b50d902SRodney W. Grimes * modification, are permitted provided that the following conditions 79b50d902SRodney W. Grimes * are met: 89b50d902SRodney W. Grimes * 1. Redistributions of source code must retain the above copyright 99b50d902SRodney W. Grimes * notice, this list of conditions and the following disclaimer. 109b50d902SRodney W. Grimes * 2. Redistributions in binary form must reproduce the above copyright 119b50d902SRodney W. Grimes * notice, this list of conditions and the following disclaimer in the 129b50d902SRodney W. Grimes * documentation and/or other materials provided with the distribution. 13fbbd9655SWarner Losh * 3. Neither the name of the University nor the names of its contributors 149b50d902SRodney W. Grimes * may be used to endorse or promote products derived from this software 159b50d902SRodney W. Grimes * without specific prior written permission. 169b50d902SRodney W. Grimes * 179b50d902SRodney W. Grimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 189b50d902SRodney W. Grimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 199b50d902SRodney W. Grimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 209b50d902SRodney W. Grimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 219b50d902SRodney W. Grimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 229b50d902SRodney W. Grimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 239b50d902SRodney W. Grimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 249b50d902SRodney W. Grimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 259b50d902SRodney W. Grimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 269b50d902SRodney W. Grimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 279b50d902SRodney W. Grimes * SUCH DAMAGE. 289b50d902SRodney W. Grimes */ 299b50d902SRodney W. Grimes 309b50d902SRodney W. Grimes #ifndef lint 31c8510085SPhilippe Charnier static const char copyright[] = 329b50d902SRodney W. Grimes "@(#) Copyright (c) 1980, 1987, 1992, 1993\n\ 339b50d902SRodney W. Grimes The Regents of the University of California. All rights reserved.\n"; 349b50d902SRodney W. Grimes #endif /* not lint */ 359b50d902SRodney W. Grimes 369b50d902SRodney W. Grimes #ifndef lint 37c8510085SPhilippe Charnier #if 0 38df3f5d9dSPeter Wemm static char sccsid[] = "@(#)head.c 8.2 (Berkeley) 5/4/95"; 39c8510085SPhilippe Charnier #endif 409b50d902SRodney W. Grimes #endif /* not lint */ 41e026a48cSDavid E. O'Brien #include <sys/cdefs.h> 42e026a48cSDavid E. O'Brien __FBSDID("$FreeBSD$"); 439b50d902SRodney W. Grimes 449b50d902SRodney W. Grimes #include <sys/types.h> 45df3f5d9dSPeter Wemm 46df3f5d9dSPeter Wemm #include <ctype.h> 47c8510085SPhilippe Charnier #include <err.h> 486e8298dbSBrooks Davis #include <inttypes.h> 49df3f5d9dSPeter Wemm #include <stdio.h> 509b50d902SRodney W. Grimes #include <stdlib.h> 519b50d902SRodney W. Grimes #include <string.h> 52df3f5d9dSPeter Wemm #include <unistd.h> 539b50d902SRodney W. Grimes 549b50d902SRodney W. Grimes /* 559b50d902SRodney W. Grimes * head - give the first few lines of a stream or of each of a set of files 569b50d902SRodney W. Grimes * 579b50d902SRodney W. Grimes * Bill Joy UCB August 24, 1977 589b50d902SRodney W. Grimes */ 599b50d902SRodney W. Grimes 604001504dSDavid Malone static void head(FILE *, int); 616e8298dbSBrooks Davis static void head_bytes(FILE *, off_t); 624001504dSDavid Malone static void obsolete(char *[]); 634001504dSDavid Malone static void usage(void); 649b50d902SRodney W. Grimes 659b50d902SRodney W. Grimes int 661abf87a8SMark Murray main(int argc, char *argv[]) 679b50d902SRodney W. Grimes { 684001504dSDavid Malone int ch; 699b50d902SRodney W. Grimes FILE *fp; 706e8298dbSBrooks Davis int first, linecnt = -1, eval = 0; 716e8298dbSBrooks Davis off_t bytecnt = -1; 729b50d902SRodney W. Grimes char *ep; 739b50d902SRodney W. Grimes 749b50d902SRodney W. Grimes obsolete(argv); 75ef0e2ea4SAlexander Langer while ((ch = getopt(argc, argv, "n:c:")) != -1) 769b50d902SRodney W. Grimes switch(ch) { 77ef0e2ea4SAlexander Langer case 'c': 786e8298dbSBrooks Davis bytecnt = strtoimax(optarg, &ep, 10); 79ef0e2ea4SAlexander Langer if (*ep || bytecnt <= 0) 80c8510085SPhilippe Charnier errx(1, "illegal byte count -- %s", optarg); 81ef0e2ea4SAlexander Langer break; 829b50d902SRodney W. Grimes case 'n': 839b50d902SRodney W. Grimes linecnt = strtol(optarg, &ep, 10); 849b50d902SRodney W. Grimes if (*ep || linecnt <= 0) 85c8510085SPhilippe Charnier errx(1, "illegal line count -- %s", optarg); 869b50d902SRodney W. Grimes break; 879b50d902SRodney W. Grimes case '?': 889b50d902SRodney W. Grimes default: 899b50d902SRodney W. Grimes usage(); 909b50d902SRodney W. Grimes } 919b50d902SRodney W. Grimes argc -= optind; 929b50d902SRodney W. Grimes argv += optind; 939b50d902SRodney W. Grimes 94ef0e2ea4SAlexander Langer if (linecnt != -1 && bytecnt != -1) 95c8510085SPhilippe Charnier errx(1, "can't combine line and byte counts"); 96ef0e2ea4SAlexander Langer if (linecnt == -1 ) 97ef0e2ea4SAlexander Langer linecnt = 10; 98ef0e2ea4SAlexander Langer if (*argv) { 999b50d902SRodney W. Grimes for (first = 1; *argv; ++argv) { 1009b50d902SRodney W. Grimes if ((fp = fopen(*argv, "r")) == NULL) { 101c8510085SPhilippe Charnier warn("%s", *argv); 10273f3d053SPhilippe Charnier eval = 1; 1039b50d902SRodney W. Grimes continue; 1049b50d902SRodney W. Grimes } 1059b50d902SRodney W. Grimes if (argc > 1) { 1069b50d902SRodney W. Grimes (void)printf("%s==> %s <==\n", 1079b50d902SRodney W. Grimes first ? "" : "\n", *argv); 1089b50d902SRodney W. Grimes first = 0; 1099b50d902SRodney W. Grimes } 110ef0e2ea4SAlexander Langer if (bytecnt == -1) 1119b50d902SRodney W. Grimes head(fp, linecnt); 112ef0e2ea4SAlexander Langer else 113ef0e2ea4SAlexander Langer head_bytes(fp, bytecnt); 1149b50d902SRodney W. Grimes (void)fclose(fp); 1159b50d902SRodney W. Grimes } 116c16b5e4fSAlfred Perlstein } else if (bytecnt == -1) 1179b50d902SRodney W. Grimes head(stdin, linecnt); 118ef0e2ea4SAlexander Langer else 119ef0e2ea4SAlexander Langer head_bytes(stdin, bytecnt); 120ef0e2ea4SAlexander Langer 1219b50d902SRodney W. Grimes exit(eval); 1229b50d902SRodney W. Grimes } 1239b50d902SRodney W. Grimes 1244001504dSDavid Malone static void 1251abf87a8SMark Murray head(FILE *fp, int cnt) 1269b50d902SRodney W. Grimes { 127c7a2aa5dSAlfred Perlstein char *cp; 1284001504dSDavid Malone size_t error, readlen; 1299b50d902SRodney W. Grimes 130c7a2aa5dSAlfred Perlstein while (cnt && (cp = fgetln(fp, &readlen)) != NULL) { 131c7a2aa5dSAlfred Perlstein error = fwrite(cp, sizeof(char), readlen, stdout); 132c7a2aa5dSAlfred Perlstein if (error != readlen) 133c8510085SPhilippe Charnier err(1, "stdout"); 1348e502f11SJoerg Wunsch cnt--; 1359b50d902SRodney W. Grimes } 1369b50d902SRodney W. Grimes } 1379b50d902SRodney W. Grimes 1384001504dSDavid Malone static void 1396e8298dbSBrooks Davis head_bytes(FILE *fp, off_t cnt) 140ef0e2ea4SAlexander Langer { 141ef0e2ea4SAlexander Langer char buf[4096]; 1424001504dSDavid Malone size_t readlen; 143ef0e2ea4SAlexander Langer 144ef0e2ea4SAlexander Langer while (cnt) { 1456137b0bdSBrooks Davis if ((uintmax_t)cnt < sizeof(buf)) 146ef0e2ea4SAlexander Langer readlen = cnt; 147ef0e2ea4SAlexander Langer else 148ef0e2ea4SAlexander Langer readlen = sizeof(buf); 149ef0e2ea4SAlexander Langer readlen = fread(buf, sizeof(char), readlen, fp); 150710668caSDag-Erling Smørgrav if (readlen == 0) 151ef0e2ea4SAlexander Langer break; 152ef0e2ea4SAlexander Langer if (fwrite(buf, sizeof(char), readlen, stdout) != readlen) 153c8510085SPhilippe Charnier err(1, "stdout"); 154ef0e2ea4SAlexander Langer cnt -= readlen; 155ef0e2ea4SAlexander Langer } 156ef0e2ea4SAlexander Langer } 157ef0e2ea4SAlexander Langer 1584001504dSDavid Malone static void 1591abf87a8SMark Murray obsolete(char *argv[]) 1609b50d902SRodney W. Grimes { 1619b50d902SRodney W. Grimes char *ap; 1629b50d902SRodney W. Grimes 163ef0e2ea4SAlexander Langer while ((ap = *++argv)) { 1649b50d902SRodney W. Grimes /* Return if "--" or not "-[0-9]*". */ 1659b50d902SRodney W. Grimes if (ap[0] != '-' || ap[1] == '-' || !isdigit(ap[1])) 1669b50d902SRodney W. Grimes return; 1679b50d902SRodney W. Grimes if ((ap = malloc(strlen(*argv) + 2)) == NULL) 168c8510085SPhilippe Charnier err(1, NULL); 1699b50d902SRodney W. Grimes ap[0] = '-'; 1709b50d902SRodney W. Grimes ap[1] = 'n'; 1719b50d902SRodney W. Grimes (void)strcpy(ap + 2, *argv + 1); 1729b50d902SRodney W. Grimes *argv = ap; 1739b50d902SRodney W. Grimes } 1749b50d902SRodney W. Grimes } 1759b50d902SRodney W. Grimes 1764001504dSDavid Malone static void 1771abf87a8SMark Murray usage(void) 1789b50d902SRodney W. Grimes { 179c16b5e4fSAlfred Perlstein 180ecca80bdSDavid Malone (void)fprintf(stderr, "usage: head [-n lines | -c bytes] [file ...]\n"); 1819b50d902SRodney W. Grimes exit(1); 1829b50d902SRodney W. Grimes } 183