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 #endif /* not lint */ 48 49 #include <sys/cdefs.h> 50 __FBSDID("$FreeBSD$"); 51 52 #include <err.h> 53 #include <stdio.h> 54 #include <stdlib.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 register int ch; 68 int width; 69 char *p; 70 71 width = -1; 72 while ((ch = getopt(argc, argv, "0123456789w:")) != -1) 73 switch (ch) { 74 case 'w': 75 if ((width = atoi(optarg)) <= 0) { 76 errx(1, "illegal width value"); 77 } 78 break; 79 case '0': case '1': case '2': case '3': case '4': 80 case '5': case '6': case '7': case '8': case '9': 81 if (width == -1) { 82 p = argv[optind - 1]; 83 if (p[0] == '-' && p[1] == ch && !p[2]) 84 width = atoi(++p); 85 else 86 width = atoi(argv[optind] + 1); 87 } 88 break; 89 default: 90 usage(); 91 } 92 argv += optind; 93 argc -= optind; 94 95 if (width == -1) 96 width = DEFLINEWIDTH; 97 if (!*argv) 98 fold(width); 99 else for (; *argv; ++argv) 100 if (!freopen(*argv, "r", stdin)) { 101 err(1, "%s", *argv); 102 } else 103 fold(width); 104 exit(0); 105 } 106 107 static void 108 usage() 109 { 110 (void)fprintf(stderr, "usage: fold [-w width] [file ...]\n"); 111 exit(1); 112 } 113 114 void 115 fold(width) 116 register int width; 117 { 118 register int ch, col, new; 119 120 for (col = 0;;) { 121 switch (ch = getchar()) { 122 case EOF: 123 return; 124 case '\b': 125 new = col ? col - 1 : 0; 126 break; 127 case '\n': 128 case '\r': 129 new = 0; 130 break; 131 case '\t': 132 new = (col + 8) & ~7; 133 break; 134 default: 135 new = col + 1; 136 break; 137 } 138 139 if (new > width) { 140 putchar('\n'); 141 col = 0; 142 } 143 putchar(ch); 144 145 switch (ch) { 146 case '\b': 147 if (col > 0) 148 --col; 149 break; 150 case '\n': 151 case '\r': 152 col = 0; 153 break; 154 case '\t': 155 col += 8; 156 col &= ~7; 157 break; 158 default: 159 ++col; 160 break; 161 } 162 } 163 } 164