1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 /* 23 * Copyright 2004 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */ 28 /* All Rights Reserved */ 29 30 /* 31 * University Copyright- Copyright (c) 1982, 1986, 1988 32 * The Regents of the University of California 33 * All Rights Reserved 34 * 35 * University Acknowledgment- Portions of this document are derived from 36 * software developed by the University of California, Berkeley, and its 37 * contributors. 38 */ 39 /* 40 * Copyright (c) 2014, Joyent, Inc. All rights reserved. 41 * Copyright 2020 Oxide Computer Company 42 */ 43 44 45 #include <stdio.h> 46 #include <stdlib.h> 47 #include <unistd.h> 48 #include <locale.h> 49 #include <string.h> 50 #include <ctype.h> 51 #include <err.h> 52 53 #define DEF_LINE_COUNT 10 54 55 static void copyout(off_t, int); 56 static void Usage(); 57 static FILE *input; 58 59 60 /* 61 * head - give the first few lines of a stream or of each of a set of files. 62 * Optionally shows a specific number of bytes instead. 63 */ 64 int 65 main(int argc, char **argv) 66 { 67 int fileCount; 68 int around = 0; 69 int i; 70 int opt; 71 off_t linecnt = DEF_LINE_COUNT; 72 int isline = 1; 73 int error = 0; 74 int quiet = 0; 75 int verbose = 0; 76 77 (void) setlocale(LC_ALL, ""); 78 #if !defined(TEXT_DOMAIN) /* Should be defined by cc -D */ 79 #define TEXT_DOMAIN "SYS_TEST" /* Use this only if it weren't */ 80 #endif 81 (void) textdomain(TEXT_DOMAIN); 82 83 /* check for non-standard "-line-count" option */ 84 for (i = 1; i < argc; i++) { 85 if (strcmp(argv[i], "--") == 0) 86 break; 87 88 if ((argv[i][0] == '-') && isdigit(argv[i][1])) { 89 if (strlen(&argv[i][1]) != 90 strspn(&argv[i][1], "0123456789")) { 91 (void) fprintf(stderr, gettext( 92 "%s: Badly formed number\n"), argv[0]); 93 Usage(); 94 } 95 96 linecnt = (off_t)strtoll(&argv[i][1], (char **)NULL, 97 10); 98 while (i < argc) { 99 argv[i] = argv[i + 1]; 100 i++; 101 } 102 argc--; 103 } 104 } 105 106 /* get options */ 107 while ((opt = getopt(argc, argv, "qvn:c:")) != EOF) { 108 switch (opt) { 109 case 'n': 110 case 'c': 111 if ((strcmp(optarg, "--") == 0) || (optind > argc)) { 112 (void) fprintf(stderr, gettext( 113 "%s: Missing -%c argument\n"), argv[0], 114 optopt); 115 Usage(); 116 } 117 linecnt = (off_t)strtoll(optarg, (char **)NULL, 10); 118 if (linecnt <= 0) { 119 (void) fprintf(stderr, gettext( 120 "%s: Invalid \"-%c %s\" option\n"), 121 argv[0], optopt, optarg); 122 Usage(); 123 } 124 isline = optopt != 'c'; 125 break; 126 case 'q': 127 quiet = 1; 128 verbose = 0; 129 break; 130 case 'v': 131 quiet = 0; 132 verbose = 1; 133 break; 134 default: 135 Usage(); 136 } 137 } 138 139 fileCount = argc - optind; 140 141 do { 142 if ((argv[optind] == NULL) && around) 143 break; 144 145 if (argv[optind] != NULL) { 146 if (input != NULL) 147 (void) fclose(input); 148 if ((input = fopen(argv[optind], "r")) == NULL) { 149 perror(argv[optind]); 150 error = 1; 151 optind++; 152 continue; 153 } 154 } else { 155 input = stdin; 156 } 157 158 if (quiet == 0) { 159 if (around) 160 (void) putchar('\n'); 161 162 if (fileCount > 1 || verbose != 0) { 163 const char *file = argv[optind]; 164 if (file == NULL) { 165 file = "standard input"; 166 } 167 (void) printf("==> %s <==\n", file); 168 } 169 } 170 171 if (argv[optind] != NULL) 172 optind++; 173 174 copyout(linecnt, isline); 175 (void) fflush(stdout); 176 around++; 177 178 } while (argv[optind] != NULL); 179 180 return (error); 181 } 182 183 static void 184 copyout(off_t cnt, int isline) 185 { 186 char lbuf[BUFSIZ]; 187 size_t len; 188 189 while (cnt > 0) { 190 len = fread(lbuf, sizeof (char), sizeof (lbuf) / sizeof (char), 191 input); 192 if (len == 0) { 193 return; 194 } 195 196 if (isline) { 197 size_t i; 198 for (i = 0; i < len; i++) { 199 if (lbuf[i] == '\n') { 200 cnt--; 201 if (cnt == 0) { 202 i++; 203 break; 204 } 205 } 206 } 207 len = i; 208 } else { 209 if (len > cnt) { 210 len = cnt; 211 } 212 cnt -= len; 213 } 214 215 if (fwrite(lbuf, sizeof (char), len, stdout) != len) { 216 err(EXIT_FAILURE, "failed to write to stdout"); 217 } 218 } 219 } 220 221 static void 222 Usage() 223 { 224 (void) printf(gettext("usage: head [-q] [-v] [-n #] [-c #] [-#] " 225 "[filename...]\n")); 226 exit(1); 227 } 228