fold.c revision 1.5
1 /*- 2 * Copyright (c) 1990 The Regents of the University of California. 3 * 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 38 char copyright[] = 39 "@(#) Copyright (c) 1990 The Regents of the University of California.\n\ 40 All rights reserved.\n"; 41 #endif /* not lint */ 42 43 #ifndef lint 44 /*static char sccsid[] = "from: @(#)fold.c 5.5 (Berkeley) 6/1/90";*/ 45 static char rcsid[] = "$Id: fold.c,v 1.5 1993/10/13 18:34:13 jtc 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 static void fold (); 57 static int new_column_position (); 58 int count_bytes = 0; 59 int split_words = 0; 60 61 int 62 main(argc, argv) 63 int argc; 64 char **argv; 65 { 66 register int ch; 67 int width; 68 char *p; 69 70 width = -1; 71 while ((ch = getopt(argc, argv, "0123456789bsw:")) != -1) 72 switch (ch) { 73 case 'b': 74 count_bytes = 1; 75 break; 76 case 's': 77 split_words = 1; 78 break; 79 case 'w': 80 if ((width = atoi(optarg)) <= 0) { 81 (void)fprintf(stderr, 82 "fold: illegal width value.\n"); 83 exit(1); 84 } 85 break; 86 case '0': case '1': case '2': case '3': case '4': 87 case '5': case '6': case '7': case '8': case '9': 88 if (width == -1) { 89 p = argv[optind - 1]; 90 if (p[0] == '-' && p[1] == ch && !p[2]) 91 width = atoi(++p); 92 else 93 width = atoi(argv[optind] + 1); 94 } 95 break; 96 default: 97 (void)fprintf(stderr, 98 "usage: fold [-bs] [-w width] [file ...]\n"); 99 exit(1); 100 } 101 argv += optind; 102 argc -= optind; 103 104 if (width == -1) 105 width = DEFLINEWIDTH; 106 107 if (!*argv) 108 fold(width); 109 else for (; *argv; ++argv) 110 if (!freopen(*argv, "r", stdin)) { 111 err (1, "%s", *argv); 112 /* NOTREACHED */ 113 } else 114 fold(width); 115 exit(0); 116 } 117 118 /* 119 * Fold the contents of standard input to fit within WIDTH columns 120 * (or bytes) and write to standard output. 121 * 122 * If split_words is set, split the line at the last space character 123 * on the line. This flag necessitates storing the line in a buffer 124 * until the current column > width, or a newline or EOF is read. 125 * 126 * The buffer can grow larger than WIDTH due to backspaces and carriage 127 * returns embedded in the input stream. 128 */ 129 static void 130 fold(width) 131 register int width; 132 { 133 static char *buf = NULL; 134 static int buf_max = 0; 135 register int ch, col; 136 register int indx; 137 138 col = indx = 0; 139 while ((ch = getchar()) != EOF) { 140 if (ch == '\n') { 141 if (indx != 0) 142 fwrite (buf, 1, indx, stdout); 143 putchar('\n'); 144 col = indx = 0; 145 continue; 146 } 147 148 col = new_column_position (col, ch); 149 if (col > width) { 150 int i, last_space; 151 152 if (split_words) { 153 for (i = 0, last_space = -1; i < indx; i++) 154 if(buf[i] == ' ') 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, ch); 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 buf_max += 2048; 181 if((buf = realloc (buf, buf_max)) == NULL) { 182 err (1, NULL); 183 /* NOTREACHED */ 184 } 185 } 186 buf[indx++] = ch; 187 } 188 189 if (indx != 0) 190 fwrite (buf, 1, indx, stdout); 191 } 192 193 /* 194 * calculate the column position 195 */ 196 static int 197 new_column_position (col, ch) 198 int col; 199 int ch; 200 { 201 if (!count_bytes) { 202 switch (ch) { 203 case '\b': 204 if (col > 0) 205 --col; 206 break; 207 case '\r': 208 col = 0; 209 break; 210 case '\t': 211 col = (col + 8) & ~7; 212 break; 213 default: 214 ++col; 215 break; 216 } 217 } else { 218 ++col; 219 } 220 221 return col; 222 } 223
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