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 */ 42 43 44 #include <stdio.h> 45 #include <stdlib.h> 46 #include <unistd.h> 47 #include <locale.h> 48 #include <string.h> 49 #include <ctype.h> 50 51 #define DEF_LINE_COUNT 10 52 53 static void copyout(off_t, int); 54 static void Usage(); 55 static FILE *input; 56 57 58 /* 59 * head - give the first few lines of a stream or of each of a set of files. 60 * Optionally shows a specific number of bytes instead. 61 */ 62 int 63 main(int argc, char **argv) 64 { 65 int fileCount; 66 int around = 0; 67 int i; 68 int opt; 69 off_t linecnt = DEF_LINE_COUNT; 70 int isline = 1; 71 int error = 0; 72 int quiet = 0; 73 74 (void) setlocale(LC_ALL, ""); 75 #if !defined(TEXT_DOMAIN) /* Should be defined by cc -D */ 76 #define TEXT_DOMAIN "SYS_TEST" /* Use this only if it weren't */ 77 #endif 78 (void) textdomain(TEXT_DOMAIN); 79 80 /* check for non-standard "-line-count" option */ 81 for (i = 1; i < argc; i++) { 82 if (strcmp(argv[i], "--") == 0) 83 break; 84 85 if ((argv[i][0] == '-') && isdigit(argv[i][1])) { 86 if (strlen(&argv[i][1]) != 87 strspn(&argv[i][1], "0123456789")) { 88 (void) fprintf(stderr, gettext( 89 "%s: Badly formed number\n"), argv[0]); 90 Usage(); 91 } 92 93 linecnt = (off_t)strtoll(&argv[i][1], (char **)NULL, 94 10); 95 while (i < argc) { 96 argv[i] = argv[i + 1]; 97 i++; 98 } 99 argc--; 100 } 101 } 102 103 /* get options */ 104 while ((opt = getopt(argc, argv, "qvn:c:")) != EOF) { 105 switch (opt) { 106 case 'n': 107 case 'c': 108 if ((strcmp(optarg, "--") == 0) || (optind > argc)) { 109 (void) fprintf(stderr, gettext( 110 "%s: Missing -%c argument\n"), argv[0], 111 optopt); 112 Usage(); 113 } 114 linecnt = (off_t)strtoll(optarg, (char **)NULL, 10); 115 if (linecnt <= 0) { 116 (void) fprintf(stderr, gettext( 117 "%s: Invalid \"-%c %s\" option\n"), 118 argv[0], optopt, optarg); 119 Usage(); 120 } 121 isline = optopt != 'c'; 122 break; 123 case 'q': 124 quiet = 1; 125 break; 126 case 'v': 127 quiet = 0; 128 break; 129 default: 130 Usage(); 131 } 132 } 133 134 fileCount = argc - optind; 135 136 do { 137 if ((argv[optind] == NULL) && around) 138 break; 139 140 if (argv[optind] != NULL) { 141 if (input != NULL) 142 (void) fclose(input); 143 if ((input = fopen(argv[optind], "r")) == NULL) { 144 perror(argv[optind]); 145 error = 1; 146 optind++; 147 continue; 148 } 149 } else { 150 input = stdin; 151 } 152 153 if (quiet == 0) { 154 if (around) 155 (void) putchar('\n'); 156 157 if (fileCount > 1) 158 (void) printf("==> %s <==\n", argv[optind]); 159 } 160 161 if (argv[optind] != NULL) 162 optind++; 163 164 copyout(linecnt, isline); 165 (void) fflush(stdout); 166 around++; 167 168 } while (argv[optind] != NULL); 169 170 return (error); 171 } 172 173 static void 174 copyout(off_t cnt, int isline) 175 { 176 char lbuf[BUFSIZ]; 177 size_t len; 178 179 while (cnt > 0 && fgets(lbuf, sizeof (lbuf), input) != 0) { 180 len = strlen(lbuf); 181 if (isline) { 182 (void) printf("%s", lbuf); 183 /* 184 * only count as a line if buffer read ends with newline 185 */ 186 if (len > 0) { 187 if (lbuf[len - 1] == '\n') { 188 (void) fflush(stdout); 189 cnt--; 190 } 191 } 192 } else { 193 if (len > cnt) { 194 lbuf[cnt] = '\0'; 195 len = cnt; 196 } 197 (void) printf("%s", lbuf); 198 cnt -= len; 199 (void) fflush(stdout); 200 } 201 } 202 } 203 204 static void 205 Usage() 206 { 207 (void) printf(gettext("usage: head [-q] [-v] [-n #] [-c #] [-#] " 208 "[filename...]\n")); 209 exit(1); 210 } 211