fold.c revision 1.14
1 /* $NetBSD: fold.c,v 1.14 2008/07/21 14:19:22 lukem Exp $ */ 2 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 #include <sys/cdefs.h> 36 #ifndef lint 37 __COPYRIGHT("@(#) Copyright (c) 1990, 1993\ 38 The Regents of the University of California. All rights reserved."); 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 __RCSID("$NetBSD: fold.c,v 1.14 2008/07/21 14:19:22 lukem Exp $"); 46 #endif /* not lint */ 47 48 #include <stdio.h> 49 #include <stdlib.h> 50 #include <string.h> 51 #include <unistd.h> 52 #include <err.h> 53 54 #define DEFLINEWIDTH 80 55 56 int main(int, char **); 57 static void fold(int); 58 static int new_column_position(int, int); 59 static void usage(void); 60 61 int count_bytes = 0; 62 int split_words = 0; 63 64 int 65 main(int argc, char **argv) 66 { 67 int ch; 68 int width; 69 char *p; 70 71 width = -1; 72 while ((ch = getopt(argc, argv, "0123456789bsw:")) != -1) 73 switch (ch) { 74 case 'b': 75 count_bytes = 1; 76 break; 77 case 's': 78 split_words = 1; 79 break; 80 case 'w': 81 if ((width = atoi(optarg)) <= 0) 82 errx(1, "illegal width value"); 83 break; 84 case '0': case '1': case '2': case '3': case '4': 85 case '5': case '6': case '7': case '8': case '9': 86 if (width == -1) { 87 p = argv[optind - 1]; 88 if (p[0] == '-' && p[1] == ch && !p[2]) 89 width = atoi(++p); 90 else 91 width = atoi(argv[optind] + 1); 92 } 93 break; 94 default: 95 usage(); 96 } 97 argv += optind; 98 argc -= optind; 99 100 if (width == -1) 101 width = DEFLINEWIDTH; 102 103 if (!*argv) 104 fold(width); 105 else for (; *argv; ++argv) 106 if (!freopen(*argv, "r", stdin)) { 107 err (1, "%s", *argv); 108 /* NOTREACHED */ 109 } else 110 fold(width); 111 exit(0); 112 } 113 114 /* 115 * Fold the contents of standard input to fit within WIDTH columns 116 * (or bytes) and write to standard output. 117 * 118 * If split_words is set, split the line at the last space character 119 * on the line. This flag necessitates storing the line in a buffer 120 * until the current column > width, or a newline or EOF is read. 121 * 122 * The buffer can grow larger than WIDTH due to backspaces and carriage 123 * returns embedded in the input stream. 124 */ 125 static void 126 fold(int width) 127 { 128 static char *buf = NULL; 129 char *nbuf; 130 static int buf_max = 0; 131 int ch, col; 132 int indx; 133 134 col = indx = 0; 135 while ((ch = getchar()) != EOF) { 136 if (ch == '\n') { 137 if (indx != 0) 138 fwrite (buf, 1, indx, stdout); 139 putchar('\n'); 140 col = indx = 0; 141 continue; 142 } 143 144 col = new_column_position (col, ch); 145 if (col > width) { 146 int i, last_space; 147 148 #ifdef __GNUC__ 149 last_space = 0; /* XXX gcc */ 150 #endif 151 if (split_words) { 152 for (i = 0, last_space = -1; i < indx; i++) 153 if (buf[i] == ' ') 154 last_space = i; 155 } 156 157 if (split_words && last_space != -1) { 158 last_space++; 159 160 fwrite (buf, 1, last_space, stdout); 161 memmove (buf, buf+last_space, indx-last_space); 162 163 indx -= last_space; 164 col = 0; 165 for (i = 0; i < indx; i++) { 166 col = new_column_position (col, buf[i]); 167 } 168 } else { 169 fwrite (buf, 1, indx, stdout); 170 col = indx = 0; 171 } 172 putchar('\n'); 173 174 /* calculate the column position for the next line. */ 175 col = new_column_position (col, ch); 176 } 177 178 if (indx + 1 > buf_max) { 179 /* Allocate buffer in LINE_MAX increments */ 180 if ((nbuf = realloc (buf, buf_max + 2048)) == NULL) { 181 err (1, "realloc"); 182 /* NOTREACHED */ 183 } 184 buf = nbuf; 185 buf_max += 2048; 186 } 187 buf[indx++] = ch; 188 } 189 190 if (indx != 0) 191 fwrite (buf, 1, indx, stdout); 192 } 193 194 /* 195 * calculate the column position 196 */ 197 static int 198 new_column_position (int col, int ch) 199 { 200 if (!count_bytes) { 201 switch (ch) { 202 case '\b': 203 if (col > 0) 204 --col; 205 break; 206 case '\r': 207 col = 0; 208 break; 209 case '\t': 210 col = (col + 8) & ~7; 211 break; 212 default: 213 ++col; 214 break; 215 } 216 } else { 217 ++col; 218 } 219 220 return col; 221 } 222 223 static void 224 usage(void) 225 { 226 (void)fprintf(stderr, 227 "usage: fold [-bs] [-w width] [file ...]\n"); 228 exit(1); 229 } 230 231
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