fold.c revision 200420
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. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 */ 36 37#ifndef lint 38static const char copyright[] = 39"@(#) Copyright (c) 1990, 1993\n\ 40 The Regents of the University of California. All rights reserved.\n"; 41#endif /* not lint */ 42 43#ifndef lint 44#if 0 45static char sccsid[] = "@(#)fold.c 8.1 (Berkeley) 6/6/93"; 46#endif 47#endif /* not lint */ 48 49#include <sys/cdefs.h> 50__FBSDID("$FreeBSD: head/usr.bin/fold/fold.c 200420 2009-12-11 23:35:38Z delphij $"); 51 52#include <err.h> 53#include <limits.h> 54#include <locale.h> 55#include <stdio.h> 56#include <stdlib.h> 57#include <unistd.h> 58#include <wchar.h> 59#include <wctype.h> 60 61#define DEFLINEWIDTH 80 62 63void fold(int); 64static int newpos(int, wint_t); 65static void usage(void); 66 67int bflag; /* Count bytes, not columns */ 68int sflag; /* Split on word boundaries */ 69 70int 71main(int argc, char **argv) 72{ 73 int ch; 74 int rval, width; 75 char *p; 76 77 (void) setlocale(LC_CTYPE, ""); 78 79 width = -1; 80 while ((ch = getopt(argc, argv, "0123456789bsw:")) != -1) 81 switch (ch) { 82 case 'b': 83 bflag = 1; 84 break; 85 case 's': 86 sflag = 1; 87 break; 88 case 'w': 89 if ((width = atoi(optarg)) <= 0) { 90 errx(1, "illegal width value"); 91 } 92 break; 93 case '0': case '1': case '2': case '3': case '4': 94 case '5': case '6': case '7': case '8': case '9': 95 if (width == -1) { 96 p = argv[optind - 1]; 97 if (p[0] == '-' && p[1] == ch && !p[2]) 98 width = atoi(++p); 99 else 100 width = atoi(argv[optind] + 1); 101 } 102 break; 103 default: 104 usage(); 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 123static void 124usage(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 */ 141void 142fold(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 */ 193static int 194newpos(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