1 /* $NetBSD: head.c,v 1.14 2001/02/19 23:03:47 cgd Exp $ */ 2 3 /* 4 * Copyright (c) 1980, 1987, 1992, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #include <sys/cdefs.h> 37 #ifndef lint 38 __COPYRIGHT("@(#) Copyright (c) 1980, 1987, 1992, 1993\n\ 39 The Regents of the University of California. All rights reserved.\n"); 40 #endif /* not lint */ 41 42 #ifndef lint 43 #if 0 44 static char sccsid[] = "@(#)head.c 8.2 (Berkeley) 5/4/95"; 45 #else 46 __RCSID("$NetBSD: head.c,v 1.14 2001/02/19 23:03:47 cgd Exp $"); 47 #endif 48 #endif /* not lint */ 49 50 #include <sys/types.h> 51 52 #include <ctype.h> 53 #include <err.h> 54 #include <errno.h> 55 #include <limits.h> 56 #include <locale.h> 57 #include <stdio.h> 58 #include <stdlib.h> 59 #include <string.h> 60 #include <unistd.h> 61 62 /* 63 * head - give the first few lines of a stream or of each of a set of files 64 * 65 * Bill Joy UCB August 24, 1977 66 */ 67 68 void head __P((FILE *, long)); 69 void obsolete __P((char *[])); 70 void usage __P((void)); 71 int main __P((int, char *[])); 72 73 int eval = 0; 74 75 int 76 main(argc, argv) 77 int argc; 78 char *argv[]; 79 { 80 int ch; 81 FILE *fp; 82 int first; 83 long linecnt; 84 char *ep; 85 86 (void)setlocale(LC_ALL, ""); 87 obsolete(argv); 88 linecnt = 10; 89 while ((ch = getopt(argc, argv, "n:")) != -1) 90 switch(ch) { 91 case 'n': 92 linecnt = strtol(optarg, &ep, 10); 93 if ((linecnt == LONG_MIN || linecnt == LONG_MAX) && 94 errno == ERANGE) 95 err(1, "illegal line count -- %s", optarg); 96 else if (*ep || linecnt <= 0) 97 errx(1, "illegal line count -- %s", optarg); 98 break; 99 100 case '?': 101 default: 102 usage(); 103 } 104 argc -= optind; 105 argv += optind; 106 107 if (*argv) 108 for (first = 1; *argv; ++argv) { 109 if ((fp = fopen(*argv, "r")) == NULL) { 110 warn("%s", *argv); 111 eval = 1; 112 continue; 113 } 114 if (argc > 1) { 115 (void)printf("%s==> %s <==\n", 116 first ? "" : "\n", *argv); 117 first = 0; 118 } 119 head(fp, linecnt); 120 (void)fclose(fp); 121 } 122 else 123 head(stdin, linecnt); 124 exit(eval); 125 } 126 127 void 128 head(fp, cnt) 129 FILE *fp; 130 long cnt; 131 { 132 int ch; 133 134 while (cnt--) 135 while ((ch = getc(fp)) != EOF) { 136 if (putchar(ch) == EOF) 137 err(1, "stdout"); 138 if (ch == '\n') 139 break; 140 } 141 } 142 143 void 144 obsolete(argv) 145 char *argv[]; 146 { 147 char *ap; 148 149 while ((ap = *++argv)) { 150 /* Return if "--" or not "-[0-9]*". */ 151 if (ap[0] != '-' || ap[1] == '-' || 152 !isdigit((unsigned char)ap[1])) 153 return; 154 if ((ap = malloc(strlen(*argv) + 2)) == NULL) 155 err(1, NULL); 156 ap[0] = '-'; 157 ap[1] = 'n'; 158 (void)strcpy(ap + 2, *argv + 1); 159 *argv = ap; 160 } 161 } 162 163 void 164 usage() 165 { 166 167 (void)fprintf(stderr, "Usage: %s [-n lines] [file ...]\n", 168 getprogname()); 169 exit(1); 170 } 171