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. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * @(#) Copyright (c) 1990, 1993 The Regents of the University of California. All rights reserved. 33 * @(#)fold.c 8.1 (Berkeley) 6/6/93 34 * $FreeBSD: src/usr.bin/fold/fold.c,v 1.4.2.3 2002/07/11 01:01:44 tjr Exp $ 35 * $DragonFly: src/usr.bin/fold/fold.c,v 1.5 2006/08/13 02:15:07 swildner Exp $ 36 */ 37 38 #include <ctype.h> 39 #include <err.h> 40 #include <limits.h> 41 #include <locale.h> 42 #include <stdio.h> 43 #include <stdlib.h> 44 #include <string.h> 45 #include <unistd.h> 46 47 #define DEFLINEWIDTH 80 48 49 void fold(int); 50 static int newpos(int, int); 51 static void usage(void); 52 53 int bflag; /* Count bytes, not columns */ 54 int sflag; /* Split on word boundaries */ 55 56 int 57 main(int argc, char **argv) 58 { 59 int ch; 60 int rval, width; 61 char *p; 62 63 (void) setlocale(LC_CTYPE, ""); 64 65 width = -1; 66 while ((ch = getopt(argc, argv, "0123456789bsw:")) != -1) 67 switch (ch) { 68 case 'b': 69 bflag = 1; 70 break; 71 case 's': 72 sflag = 1; 73 break; 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 rval = 0; 98 if (!*argv) 99 fold(width); 100 else for (; *argv; ++argv) 101 if (!freopen(*argv, "r", stdin)) { 102 warn("%s", *argv); 103 rval = 1; 104 } else 105 fold(width); 106 exit(rval); 107 } 108 109 static void 110 usage(void) 111 { 112 (void)fprintf(stderr, "usage: fold [-bs] [-w width] [file ...]\n"); 113 exit(1); 114 } 115 116 /* 117 * Fold the contents of standard input to fit within WIDTH columns (or bytes) 118 * and write to standard output. 119 * 120 * If sflag is set, split the line at the last space character on the line. 121 * This flag necessitates storing the line in a buffer until the current 122 * column > width, or a newline or EOF is read. 123 * 124 * The buffer can grow larger than WIDTH due to backspaces and carriage 125 * returns embedded in the input stream. 126 */ 127 void 128 fold(int width) 129 { 130 static char *buf; 131 static int buf_max; 132 int ch, col, i, indx, space; 133 134 col = indx = space = 0; 135 while ((ch = getchar()) != EOF) { 136 if (ch == '\n') { 137 if (indx != 0) 138 fwrite(buf, 1, indx, stdout); 139 putchar('\n'); 140 col = indx = 0; 141 continue; 142 } 143 if ((col = newpos(col, ch)) > width) { 144 if (sflag) { 145 i = indx; 146 while (--i >= 0 && !isblank((unsigned char)buf[i])) 147 ; 148 space = i; 149 } 150 if (sflag && space != -1) { 151 space++; 152 fwrite(buf, 1, space, stdout); 153 memmove(buf, buf + space, indx - space); 154 indx -= space; 155 col = 0; 156 for (i = 0; i < indx; i++) 157 col = newpos(col, 158 (unsigned char)buf[i]); 159 } else { 160 fwrite(buf, 1, indx, stdout); 161 col = indx = 0; 162 } 163 putchar('\n'); 164 col = newpos(col, ch); 165 } 166 if (indx + 1 > buf_max) { 167 buf_max += LINE_MAX; 168 if ((buf = realloc(buf, buf_max)) == NULL) 169 err(1, "realloc()"); 170 } 171 buf[indx++] = ch; 172 } 173 174 if (indx != 0) 175 fwrite(buf, 1, indx, stdout); 176 } 177 178 /* 179 * Update the current column position for a character. 180 */ 181 static int 182 newpos(int col, int ch) 183 { 184 185 if (bflag) 186 ++col; 187 else 188 switch (ch) { 189 case '\b': 190 if (col > 0) 191 --col; 192 break; 193 case '\r': 194 col = 0; 195 break; 196 case '\t': 197 col = (col + 8) & ~7; 198 break; 199 default: 200 if (isprint(ch)) 201 ++col; 202 break; 203 } 204 205 return (col); 206 } 207