1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1990, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Kevin Ruddy. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 #include <err.h> 36 #include <limits.h> 37 #include <locale.h> 38 #include <stdio.h> 39 #include <stdlib.h> 40 #include <string.h> 41 #include <unistd.h> 42 #include <wchar.h> 43 #include <wctype.h> 44 45 #define DEFLINEWIDTH 80 46 47 void fold(int); 48 static int newpos(int, wint_t); 49 static void usage(void) __dead2; 50 51 static int bflag; /* Count bytes, not columns */ 52 static int sflag; /* Split on word boundaries */ 53 54 int 55 main(int argc, char **argv) 56 { 57 int ch, previous_ch; 58 int rval, width; 59 60 (void) setlocale(LC_CTYPE, ""); 61 62 width = -1; 63 previous_ch = 0; 64 while ((ch = getopt(argc, argv, "0123456789bsw:")) != -1) { 65 switch (ch) { 66 case 'b': 67 bflag = 1; 68 break; 69 case 's': 70 sflag = 1; 71 break; 72 case 'w': 73 if ((width = atoi(optarg)) <= 0) { 74 errx(1, "illegal width value"); 75 } 76 break; 77 case '0': case '1': case '2': case '3': case '4': 78 case '5': case '6': case '7': case '8': case '9': 79 /* Accept a width as eg. -30. Note that a width 80 * specified using the -w option is always used prior 81 * to this undocumented option. */ 82 switch (previous_ch) { 83 case '0': case '1': case '2': case '3': case '4': 84 case '5': case '6': case '7': case '8': case '9': 85 /* The width is a number with multiple digits: 86 * add the last one. */ 87 width = width * 10 + (ch - '0'); 88 break; 89 default: 90 /* Set the width, unless it was previously 91 * set. For instance, the following options 92 * would all give a width of 5 and not 10: 93 * -10 -w5 94 * -5b10 95 * -5 -10b */ 96 if (width == -1) 97 width = ch - '0'; 98 break; 99 } 100 break; 101 default: 102 usage(); 103 } 104 previous_ch = ch; 105 } 106 argv += optind; 107 argc -= optind; 108 109 if (width == -1) 110 width = DEFLINEWIDTH; 111 rval = 0; 112 if (!*argv) 113 fold(width); 114 else for (; *argv; ++argv) 115 if (!freopen(*argv, "r", stdin)) { 116 warn("%s", *argv); 117 rval = 1; 118 } else 119 fold(width); 120 exit(rval); 121 } 122 123 static void 124 usage(void) 125 { 126 (void)fprintf(stderr, "usage: fold [-bs] [-w width] [file ...]\n"); 127 exit(1); 128 } 129 130 /* 131 * Fold the contents of standard input to fit within WIDTH columns (or bytes) 132 * and write to standard output. 133 * 134 * If sflag is set, split the line at the last space character on the line. 135 * This flag necessitates storing the line in a buffer until the current 136 * column > width, or a newline or EOF is read. 137 * 138 * The buffer can grow larger than WIDTH due to backspaces and carriage 139 * returns embedded in the input stream. 140 */ 141 void 142 fold(int width) 143 { 144 static wchar_t *buf; 145 static int buf_max; 146 int col, i, indx, space; 147 wint_t ch; 148 149 col = indx = 0; 150 while ((ch = getwchar()) != WEOF) { 151 if (ch == '\n') { 152 wprintf(L"%.*ls\n", indx, buf); 153 col = indx = 0; 154 continue; 155 } 156 if ((col = newpos(col, ch)) > width) { 157 if (sflag) { 158 i = indx; 159 while (--i >= 0 && !iswblank(buf[i])) 160 ; 161 space = i; 162 } 163 if (sflag && space != -1) { 164 space++; 165 wprintf(L"%.*ls\n", space, buf); 166 wmemmove(buf, buf + space, indx - space); 167 indx -= space; 168 col = 0; 169 for (i = 0; i < indx; i++) 170 col = newpos(col, buf[i]); 171 } else { 172 wprintf(L"%.*ls\n", indx, buf); 173 col = indx = 0; 174 } 175 col = newpos(col, ch); 176 } 177 if (indx + 1 > buf_max) { 178 buf_max += LINE_MAX; 179 buf = realloc(buf, sizeof(*buf) * buf_max); 180 if (buf == NULL) 181 err(1, "realloc()"); 182 } 183 buf[indx++] = ch; 184 } 185 186 if (indx != 0) 187 wprintf(L"%.*ls", indx, buf); 188 } 189 190 /* 191 * Update the current column position for a character. 192 */ 193 static int 194 newpos(int col, wint_t ch) 195 { 196 char buf[MB_LEN_MAX]; 197 size_t len; 198 int w; 199 200 if (bflag) { 201 len = wcrtomb(buf, ch, NULL); 202 col += len; 203 } else 204 switch (ch) { 205 case '\b': 206 if (col > 0) 207 --col; 208 break; 209 case '\r': 210 col = 0; 211 break; 212 case '\t': 213 col = (col + 8) & ~7; 214 break; 215 default: 216 if ((w = wcwidth(ch)) > 0) 217 col += w; 218 break; 219 } 220 221 return (col); 222 } 223