fold.c revision 95033
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 95033 2002-04-19 09:02:16Z ache $"); 51 52#include <ctype.h> 53#include <err.h> 54#include <limits.h> 55#include <locale.h> 56#include <stdio.h> 57#include <stdlib.h> 58#include <string.h> 59#include <unistd.h> 60 61#define DEFLINEWIDTH 80 62 63void fold(int); 64static int newpos(int, int); 65static void usage(void); 66 67int bflag; /* Count bytes, not columns */ 68int sflag; /* Split on word boundaries */ 69 70int 71main(argc, argv) 72 int argc; 73 char **argv; 74{ 75 register int ch; 76 int width; 77 char *p; 78 79 (void) setlocale(LC_CTYPE, ""); 80 81 width = -1; 82 while ((ch = getopt(argc, argv, "0123456789bsw:")) != -1) 83 switch (ch) { 84 case 'b': 85 bflag = 1; 86 break; 87 case 's': 88 sflag = 1; 89 break; 90 case 'w': 91 if ((width = atoi(optarg)) <= 0) { 92 errx(1, "illegal width value"); 93 } 94 break; 95 case '0': case '1': case '2': case '3': case '4': 96 case '5': case '6': case '7': case '8': case '9': 97 if (width == -1) { 98 p = argv[optind - 1]; 99 if (p[0] == '-' && p[1] == ch && !p[2]) 100 width = atoi(++p); 101 else 102 width = atoi(argv[optind] + 1); 103 } 104 break; 105 default: 106 usage(); 107 } 108 argv += optind; 109 argc -= optind; 110 111 if (width == -1) 112 width = DEFLINEWIDTH; 113 if (!*argv) 114 fold(width); 115 else for (; *argv; ++argv) 116 if (!freopen(*argv, "r", stdin)) { 117 err(1, "%s", *argv); 118 } else 119 fold(width); 120 exit(0); 121} 122 123static void 124usage() 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(width) 143 register int width; 144{ 145 static char *buf; 146 static int buf_max; 147 int ch, col, i, indx, space; 148 149 col = indx = 0; 150 while ((ch = getchar()) != EOF) { 151 if (ch == '\n') { 152 if (indx != 0) 153 fwrite(buf, 1, indx, stdout); 154 putchar('\n'); 155 col = indx = 0; 156 continue; 157 } 158 if ((col = newpos(col, ch)) > width) { 159 if (sflag) { 160 i = indx; 161 while (--i >= 0 && !isblank((unsigned char)buf[i])) 162 ; 163 space = i; 164 } 165 if (sflag && space != -1) { 166 space++; 167 fwrite(buf, 1, space, stdout); 168 memmove(buf, buf + space, indx - space); 169 indx -= space; 170 col = 0; 171 for (i = 0; i < indx; i++) 172 col = newpos(col, buf[i]); 173 } else { 174 fwrite(buf, 1, indx, stdout); 175 col = indx = 0; 176 } 177 putchar('\n'); 178 col = newpos(col, ch); 179 } 180 if (indx + 1 > buf_max) { 181 buf_max += LINE_MAX; 182 if ((buf = realloc(buf, buf_max)) == NULL) 183 err(1, "realloc()"); 184 } 185 buf[indx++] = ch; 186 } 187 188 if (indx != 0) 189 fwrite(buf, 1, indx, stdout); 190} 191 192/* 193 * Update the current column position for a character. 194 */ 195static int 196newpos(col, ch) 197 int col, ch; 198{ 199 200 if (bflag) 201 ++col; 202 else 203 switch (ch) { 204 case '\b': 205 if (col > 0) 206 --col; 207 break; 208 case '\r': 209 col = 0; 210 break; 211 case '\t': 212 col = (col + 8) & ~7; 213 break; 214 default: 215 ++col; 216 break; 217 } 218 219 return (col); 220} 221