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 * 4. 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 33 #ifndef lint 34 static const char copyright[] = 35 "@(#) Copyright (c) 1990, 1993\n\ 36 The Regents of the University of California. All rights reserved.\n"; 37 #endif /* not lint */ 38 39 #ifndef lint 40 #if 0 41 static char sccsid[] = "@(#)fold.c 8.1 (Berkeley) 6/6/93"; 42 #endif 43 #endif /* not lint */ 44 45 #include <sys/cdefs.h> 46 __FBSDID("$FreeBSD$"); 47 48 #include <capsicum_helpers.h> 49 #include <err.h> 50 #include <limits.h> 51 #include <locale.h> 52 #include <stdio.h> 53 #include <stdlib.h> 54 #include <string.h> 55 #include <unistd.h> 56 #include <wchar.h> 57 #include <wctype.h> 58 59 #define DEFLINEWIDTH 80 60 61 void fold(int); 62 static int newpos(int, wint_t); 63 static void usage(void); 64 65 static int bflag; /* Count bytes, not columns */ 66 static int sflag; /* Split on word boundaries */ 67 68 int 69 main(int argc, char **argv) 70 { 71 int ch, previous_ch; 72 int rval, width; 73 74 (void) setlocale(LC_CTYPE, ""); 75 76 if (caph_limit_stdio() < 0 || (cap_enter() < 0 && errno != ENOSYS)) 77 err(1, "capsicum"); 78 79 width = -1; 80 previous_ch = 0; 81 while ((ch = getopt(argc, argv, "0123456789bsw:")) != -1) { 82 switch (ch) { 83 case 'b': 84 bflag = 1; 85 break; 86 case 's': 87 sflag = 1; 88 break; 89 case 'w': 90 if ((width = atoi(optarg)) <= 0) { 91 errx(1, "illegal width value"); 92 } 93 break; 94 case '0': case '1': case '2': case '3': case '4': 95 case '5': case '6': case '7': case '8': case '9': 96 /* Accept a width as eg. -30. Note that a width 97 * specified using the -w option is always used prior 98 * to this undocumented option. */ 99 switch (previous_ch) { 100 case '0': case '1': case '2': case '3': case '4': 101 case '5': case '6': case '7': case '8': case '9': 102 /* The width is a number with multiple digits: 103 * add the last one. */ 104 width = width * 10 + (ch - '0'); 105 break; 106 default: 107 /* Set the width, unless it was previously 108 * set. For instance, the following options 109 * would all give a width of 5 and not 10: 110 * -10 -w5 111 * -5b10 112 * -5 -10b */ 113 if (width == -1) 114 width = ch - '0'; 115 break; 116 } 117 break; 118 default: 119 usage(); 120 } 121 previous_ch = ch; 122 } 123 argv += optind; 124 argc -= optind; 125 126 if (width == -1) 127 width = DEFLINEWIDTH; 128 rval = 0; 129 if (!*argv) 130 fold(width); 131 else for (; *argv; ++argv) 132 if (!freopen(*argv, "r", stdin)) { 133 warn("%s", *argv); 134 rval = 1; 135 } else 136 fold(width); 137 exit(rval); 138 } 139 140 static void 141 usage(void) 142 { 143 (void)fprintf(stderr, "usage: fold [-bs] [-w width] [file ...]\n"); 144 exit(1); 145 } 146 147 /* 148 * Fold the contents of standard input to fit within WIDTH columns (or bytes) 149 * and write to standard output. 150 * 151 * If sflag is set, split the line at the last space character on the line. 152 * This flag necessitates storing the line in a buffer until the current 153 * column > width, or a newline or EOF is read. 154 * 155 * The buffer can grow larger than WIDTH due to backspaces and carriage 156 * returns embedded in the input stream. 157 */ 158 void 159 fold(int width) 160 { 161 static wchar_t *buf; 162 static int buf_max; 163 int col, i, indx, space; 164 wint_t ch; 165 166 col = indx = 0; 167 while ((ch = getwchar()) != WEOF) { 168 if (ch == '\n') { 169 wprintf(L"%.*ls\n", indx, buf); 170 col = indx = 0; 171 continue; 172 } 173 if ((col = newpos(col, ch)) > width) { 174 if (sflag) { 175 i = indx; 176 while (--i >= 0 && !iswblank(buf[i])) 177 ; 178 space = i; 179 } 180 if (sflag && space != -1) { 181 space++; 182 wprintf(L"%.*ls\n", space, buf); 183 wmemmove(buf, buf + space, indx - space); 184 indx -= space; 185 col = 0; 186 for (i = 0; i < indx; i++) 187 col = newpos(col, buf[i]); 188 } else { 189 wprintf(L"%.*ls\n", indx, buf); 190 col = indx = 0; 191 } 192 col = newpos(col, ch); 193 } 194 if (indx + 1 > buf_max) { 195 buf_max += LINE_MAX; 196 buf = realloc(buf, sizeof(*buf) * buf_max); 197 if (buf == NULL) 198 err(1, "realloc()"); 199 } 200 buf[indx++] = ch; 201 } 202 203 if (indx != 0) 204 wprintf(L"%.*ls", indx, buf); 205 } 206 207 /* 208 * Update the current column position for a character. 209 */ 210 static int 211 newpos(int col, wint_t ch) 212 { 213 char buf[MB_LEN_MAX]; 214 size_t len; 215 int w; 216 217 if (bflag) { 218 len = wcrtomb(buf, ch, NULL); 219 col += len; 220 } else 221 switch (ch) { 222 case '\b': 223 if (col > 0) 224 --col; 225 break; 226 case '\r': 227 col = 0; 228 break; 229 case '\t': 230 col = (col + 8) & ~7; 231 break; 232 default: 233 if ((w = wcwidth(ch)) > 0) 234 col += w; 235 break; 236 } 237 238 return (col); 239 } 240