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 #ifndef lint 36 static const char copyright[] = 37 "@(#) Copyright (c) 1990, 1993\n\ 38 The Regents of the University of California. All rights reserved.\n"; 39 #endif /* not lint */ 40 41 #ifndef lint 42 #if 0 43 static char sccsid[] = "@(#)fold.c 8.1 (Berkeley) 6/6/93"; 44 #endif 45 #endif /* not lint */ 46 47 #include <sys/cdefs.h> 48 #include <err.h> 49 #include <limits.h> 50 #include <locale.h> 51 #include <stdio.h> 52 #include <stdlib.h> 53 #include <string.h> 54 #include <unistd.h> 55 #include <wchar.h> 56 #include <wctype.h> 57 58 #define DEFLINEWIDTH 80 59 60 void fold(int); 61 static int newpos(int, wint_t); 62 static void usage(void) __dead2; 63 64 static int bflag; /* Count bytes, not columns */ 65 static int sflag; /* Split on word boundaries */ 66 67 int 68 main(int argc, char **argv) 69 { 70 int ch, previous_ch; 71 int rval, width; 72 73 (void) setlocale(LC_CTYPE, ""); 74 75 width = -1; 76 previous_ch = 0; 77 while ((ch = getopt(argc, argv, "0123456789bsw:")) != -1) { 78 switch (ch) { 79 case 'b': 80 bflag = 1; 81 break; 82 case 's': 83 sflag = 1; 84 break; 85 case 'w': 86 if ((width = atoi(optarg)) <= 0) { 87 errx(1, "illegal width value"); 88 } 89 break; 90 case '0': case '1': case '2': case '3': case '4': 91 case '5': case '6': case '7': case '8': case '9': 92 /* Accept a width as eg. -30. Note that a width 93 * specified using the -w option is always used prior 94 * to this undocumented option. */ 95 switch (previous_ch) { 96 case '0': case '1': case '2': case '3': case '4': 97 case '5': case '6': case '7': case '8': case '9': 98 /* The width is a number with multiple digits: 99 * add the last one. */ 100 width = width * 10 + (ch - '0'); 101 break; 102 default: 103 /* Set the width, unless it was previously 104 * set. For instance, the following options 105 * would all give a width of 5 and not 10: 106 * -10 -w5 107 * -5b10 108 * -5 -10b */ 109 if (width == -1) 110 width = ch - '0'; 111 break; 112 } 113 break; 114 default: 115 usage(); 116 } 117 previous_ch = ch; 118 } 119 argv += optind; 120 argc -= optind; 121 122 if (width == -1) 123 width = DEFLINEWIDTH; 124 rval = 0; 125 if (!*argv) 126 fold(width); 127 else for (; *argv; ++argv) 128 if (!freopen(*argv, "r", stdin)) { 129 warn("%s", *argv); 130 rval = 1; 131 } else 132 fold(width); 133 exit(rval); 134 } 135 136 static void 137 usage(void) 138 { 139 (void)fprintf(stderr, "usage: fold [-bs] [-w width] [file ...]\n"); 140 exit(1); 141 } 142 143 /* 144 * Fold the contents of standard input to fit within WIDTH columns (or bytes) 145 * and write to standard output. 146 * 147 * If sflag is set, split the line at the last space character on the line. 148 * This flag necessitates storing the line in a buffer until the current 149 * column > width, or a newline or EOF is read. 150 * 151 * The buffer can grow larger than WIDTH due to backspaces and carriage 152 * returns embedded in the input stream. 153 */ 154 void 155 fold(int width) 156 { 157 static wchar_t *buf; 158 static int buf_max; 159 int col, i, indx, space; 160 wint_t ch; 161 162 col = indx = 0; 163 while ((ch = getwchar()) != WEOF) { 164 if (ch == '\n') { 165 wprintf(L"%.*ls\n", indx, buf); 166 col = indx = 0; 167 continue; 168 } 169 if ((col = newpos(col, ch)) > width) { 170 if (sflag) { 171 i = indx; 172 while (--i >= 0 && !iswblank(buf[i])) 173 ; 174 space = i; 175 } 176 if (sflag && space != -1) { 177 space++; 178 wprintf(L"%.*ls\n", space, buf); 179 wmemmove(buf, buf + space, indx - space); 180 indx -= space; 181 col = 0; 182 for (i = 0; i < indx; i++) 183 col = newpos(col, buf[i]); 184 } else { 185 wprintf(L"%.*ls\n", indx, buf); 186 col = indx = 0; 187 } 188 col = newpos(col, ch); 189 } 190 if (indx + 1 > buf_max) { 191 buf_max += LINE_MAX; 192 buf = realloc(buf, sizeof(*buf) * buf_max); 193 if (buf == NULL) 194 err(1, "realloc()"); 195 } 196 buf[indx++] = ch; 197 } 198 199 if (indx != 0) 200 wprintf(L"%.*ls", indx, buf); 201 } 202 203 /* 204 * Update the current column position for a character. 205 */ 206 static int 207 newpos(int col, wint_t ch) 208 { 209 char buf[MB_LEN_MAX]; 210 size_t len; 211 int w; 212 213 if (bflag) { 214 len = wcrtomb(buf, ch, NULL); 215 col += len; 216 } else 217 switch (ch) { 218 case '\b': 219 if (col > 0) 220 --col; 221 break; 222 case '\r': 223 col = 0; 224 break; 225 case '\t': 226 col = (col + 8) & ~7; 227 break; 228 default: 229 if ((w = wcwidth(ch)) > 0) 230 col += w; 231 break; 232 } 233 234 return (col); 235 } 236