1 /*- 2 * Copyright (c) 1990, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Kevin Ruddy. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 */ 36 37 #ifndef lint 38 static const char copyright[] = 39 "@(#) Copyright (c) 1990, 1993\n\ 40 The Regents of the University of California. All rights reserved.\n"; 41 #endif /* not lint */ 42 43 #ifndef lint 44 #if 0 45 static char sccsid[] = "@(#)fold.c 8.1 (Berkeley) 6/6/93"; 46 #endif 47 static const char rcsid[] = 48 "$FreeBSD$"; 49 #endif /* not lint */ 50 51 #include <err.h> 52 #include <stdio.h> 53 #include <stdlib.h> 54 #include <string.h> 55 #include <unistd.h> 56 57 #define DEFLINEWIDTH 80 58 59 void fold __P((int)); 60 static void usage __P((void)); 61 62 int 63 main(argc, argv) 64 int argc; 65 char **argv; 66 { 67 extern int optind; 68 extern char *optarg; 69 register int ch; 70 int width; 71 char *p; 72 73 width = -1; 74 while ((ch = getopt(argc, argv, "0123456789w:")) != -1) 75 switch (ch) { 76 case 'w': 77 if ((width = atoi(optarg)) <= 0) { 78 errx(1, "illegal width value"); 79 } 80 break; 81 case '0': case '1': case '2': case '3': case '4': 82 case '5': case '6': case '7': case '8': case '9': 83 if (width == -1) { 84 p = argv[optind - 1]; 85 if (p[0] == '-' && p[1] == ch && !p[2]) 86 width = atoi(++p); 87 else 88 width = atoi(argv[optind] + 1); 89 } 90 break; 91 default: 92 usage(); 93 } 94 argv += optind; 95 argc -= optind; 96 97 if (width == -1) 98 width = DEFLINEWIDTH; 99 if (!*argv) 100 fold(width); 101 else for (; *argv; ++argv) 102 if (!freopen(*argv, "r", stdin)) { 103 err(1, "%s", *argv); 104 } else 105 fold(width); 106 exit(0); 107 } 108 109 static void 110 usage() 111 { 112 (void)fprintf(stderr, "usage: fold [-w width] [file ...]\n"); 113 exit(1); 114 } 115 116 void 117 fold(width) 118 register int width; 119 { 120 register int ch, col, new; 121 122 for (col = 0;;) { 123 switch (ch = getchar()) { 124 case EOF: 125 return; 126 case '\b': 127 new = col ? col - 1 : 0; 128 break; 129 case '\n': 130 case '\r': 131 new = 0; 132 break; 133 case '\t': 134 new = (col + 8) & ~7; 135 break; 136 default: 137 new = col + 1; 138 break; 139 } 140 141 if (new > width) { 142 putchar('\n'); 143 col = 0; 144 } 145 putchar(ch); 146 147 switch (ch) { 148 case '\b': 149 if (col > 0) 150 --col; 151 break; 152 case '\n': 153 case '\r': 154 col = 0; 155 break; 156 case '\t': 157 col += 8; 158 col &= ~7; 159 break; 160 default: 161 ++col; 162 break; 163 } 164 } 165 } 166