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 __FBSDID("$FreeBSD$"); 49 50 #include <err.h> 51 #include <limits.h> 52 #include <locale.h> 53 #include <stdio.h> 54 #include <stdlib.h> 55 #include <string.h> 56 #include <unistd.h> 57 #include <wchar.h> 58 #include <wctype.h> 59 60 #define DEFLINEWIDTH 80 61 62 void fold(int); 63 static int newpos(int, wint_t); 64 static void usage(void); 65 66 static int bflag; /* Count bytes, not columns */ 67 static int sflag; /* Split on word boundaries */ 68 69 int 70 main(int argc, char **argv) 71 { 72 int ch, previous_ch; 73 int rval, width; 74 75 (void) setlocale(LC_CTYPE, ""); 76 77 width = -1; 78 previous_ch = 0; 79 while ((ch = getopt(argc, argv, "0123456789bsw:")) != -1) { 80 switch (ch) { 81 case 'b': 82 bflag = 1; 83 break; 84 case 's': 85 sflag = 1; 86 break; 87 case 'w': 88 if ((width = atoi(optarg)) <= 0) { 89 errx(1, "illegal width value"); 90 } 91 break; 92 case '0': case '1': case '2': case '3': case '4': 93 case '5': case '6': case '7': case '8': case '9': 94 /* Accept a width as eg. -30. Note that a width 95 * specified using the -w option is always used prior 96 * to this undocumented option. */ 97 switch (previous_ch) { 98 case '0': case '1': case '2': case '3': case '4': 99 case '5': case '6': case '7': case '8': case '9': 100 /* The width is a number with multiple digits: 101 * add the last one. */ 102 width = width * 10 + (ch - '0'); 103 break; 104 default: 105 /* Set the width, unless it was previously 106 * set. For instance, the following options 107 * would all give a width of 5 and not 10: 108 * -10 -w5 109 * -5b10 110 * -5 -10b */ 111 if (width == -1) 112 width = ch - '0'; 113 break; 114 } 115 break; 116 default: 117 usage(); 118 } 119 previous_ch = ch; 120 } 121 argv += optind; 122 argc -= optind; 123 124 if (width == -1) 125 width = DEFLINEWIDTH; 126 rval = 0; 127 if (!*argv) 128 fold(width); 129 else for (; *argv; ++argv) 130 if (!freopen(*argv, "r", stdin)) { 131 warn("%s", *argv); 132 rval = 1; 133 } else 134 fold(width); 135 exit(rval); 136 } 137 138 static void 139 usage(void) 140 { 141 (void)fprintf(stderr, "usage: fold [-bs] [-w width] [file ...]\n"); 142 exit(1); 143 } 144 145 /* 146 * Fold the contents of standard input to fit within WIDTH columns (or bytes) 147 * and write to standard output. 148 * 149 * If sflag is set, split the line at the last space character on the line. 150 * This flag necessitates storing the line in a buffer until the current 151 * column > width, or a newline or EOF is read. 152 * 153 * The buffer can grow larger than WIDTH due to backspaces and carriage 154 * returns embedded in the input stream. 155 */ 156 void 157 fold(int width) 158 { 159 static wchar_t *buf; 160 static int buf_max; 161 int col, i, indx, space; 162 wint_t ch; 163 164 col = indx = 0; 165 while ((ch = getwchar()) != WEOF) { 166 if (ch == '\n') { 167 wprintf(L"%.*ls\n", indx, buf); 168 col = indx = 0; 169 continue; 170 } 171 if ((col = newpos(col, ch)) > width) { 172 if (sflag) { 173 i = indx; 174 while (--i >= 0 && !iswblank(buf[i])) 175 ; 176 space = i; 177 } 178 if (sflag && space != -1) { 179 space++; 180 wprintf(L"%.*ls\n", space, buf); 181 wmemmove(buf, buf + space, indx - space); 182 indx -= space; 183 col = 0; 184 for (i = 0; i < indx; i++) 185 col = newpos(col, buf[i]); 186 } else { 187 wprintf(L"%.*ls\n", indx, buf); 188 col = indx = 0; 189 } 190 col = newpos(col, ch); 191 } 192 if (indx + 1 > buf_max) { 193 buf_max += LINE_MAX; 194 buf = realloc(buf, sizeof(*buf) * buf_max); 195 if (buf == NULL) 196 err(1, "realloc()"); 197 } 198 buf[indx++] = ch; 199 } 200 201 if (indx != 0) 202 wprintf(L"%.*ls", indx, buf); 203 } 204 205 /* 206 * Update the current column position for a character. 207 */ 208 static int 209 newpos(int col, wint_t ch) 210 { 211 char buf[MB_LEN_MAX]; 212 size_t len; 213 int w; 214 215 if (bflag) { 216 len = wcrtomb(buf, ch, NULL); 217 col += len; 218 } else 219 switch (ch) { 220 case '\b': 221 if (col > 0) 222 --col; 223 break; 224 case '\r': 225 col = 0; 226 break; 227 case '\t': 228 col = (col + 8) & ~7; 229 break; 230 default: 231 if ((w = wcwidth(ch)) > 0) 232 col += w; 233 break; 234 } 235 236 return (col); 237 } 238