fold.c revision 1.6
1 /* $NetBSD: fold.c,v 1.6 1995/09/01 01:42:44 jtc 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. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 */ 38 39 #ifndef lint 40 static char copyright[] = 41 "@(#) Copyright (c) 1990, 1993\n\ 42 The Regents of the University of California. All rights reserved.\n"; 43 #endif /* not lint */ 44 45 #ifndef lint 46 #if 0 47 static char sccsid[] = "@(#)fold.c 8.1 (Berkeley) 6/6/93"; 48 #endif 49 static char rcsid[] = "$NetBSD: fold.c,v 1.6 1995/09/01 01:42:44 jtc Exp $"; 50 #endif /* not lint */ 51 52 #include <stdio.h> 53 #include <stdlib.h> 54 #include <string.h> 55 #include <unistd.h> 56 #include <err.h> 57 58 #define DEFLINEWIDTH 80 59 60 static void fold (); 61 static int new_column_position (); 62 int count_bytes = 0; 63 int split_words = 0; 64 65 int 66 main(argc, argv) 67 int argc; 68 char **argv; 69 { 70 register int ch; 71 int width; 72 char *p; 73 74 width = -1; 75 while ((ch = getopt(argc, argv, "0123456789bsw:")) != -1) 76 switch (ch) { 77 case 'b': 78 count_bytes = 1; 79 break; 80 case 's': 81 split_words = 1; 82 break; 83 case 'w': 84 if ((width = atoi(optarg)) <= 0) { 85 (void)fprintf(stderr, 86 "fold: illegal width value.\n"); 87 exit(1); 88 } 89 break; 90 case '0': case '1': case '2': case '3': case '4': 91 case '5': case '6': case '7': case '8': case '9': 92 if (width == -1) { 93 p = argv[optind - 1]; 94 if (p[0] == '-' && p[1] == ch && !p[2]) 95 width = atoi(++p); 96 else 97 width = atoi(argv[optind] + 1); 98 } 99 break; 100 default: 101 (void)fprintf(stderr, 102 "usage: fold [-bs] [-w width] [file ...]\n"); 103 exit(1); 104 } 105 argv += optind; 106 argc -= optind; 107 108 if (width == -1) 109 width = DEFLINEWIDTH; 110 111 if (!*argv) 112 fold(width); 113 else for (; *argv; ++argv) 114 if (!freopen(*argv, "r", stdin)) { 115 err (1, "%s", *argv); 116 /* NOTREACHED */ 117 } else 118 fold(width); 119 exit(0); 120 } 121 122 /* 123 * Fold the contents of standard input to fit within WIDTH columns 124 * (or bytes) and write to standard output. 125 * 126 * If split_words is set, split the line at the last space character 127 * on the line. This flag necessitates storing the line in a buffer 128 * until the current column > width, or a newline or EOF is read. 129 * 130 * The buffer can grow larger than WIDTH due to backspaces and carriage 131 * returns embedded in the input stream. 132 */ 133 static void 134 fold(width) 135 register int width; 136 { 137 static char *buf = NULL; 138 static int buf_max = 0; 139 register int ch, col; 140 register int indx; 141 142 col = indx = 0; 143 while ((ch = getchar()) != EOF) { 144 if (ch == '\n') { 145 if (indx != 0) 146 fwrite (buf, 1, indx, stdout); 147 putchar('\n'); 148 col = indx = 0; 149 continue; 150 } 151 152 col = new_column_position (col, ch); 153 if (col > width) { 154 int i, last_space; 155 156 if (split_words) { 157 for (i = 0, last_space = -1; i < indx; i++) 158 if(buf[i] == ' ') last_space = i; 159 } 160 161 if (split_words && last_space != -1) { 162 last_space++; 163 164 fwrite (buf, 1, last_space, stdout); 165 memmove (buf, buf+last_space, indx-last_space); 166 167 indx -= last_space; 168 col = 0; 169 for (i = 0; i < indx; i++) { 170 col = new_column_position (col, ch); 171 } 172 } else { 173 fwrite (buf, 1, indx, stdout); 174 col = indx = 0; 175 } 176 putchar('\n'); 177 178 /* calculate the column position for the next line. */ 179 col = new_column_position (col, ch); 180 } 181 182 if (indx + 1 > buf_max) { 183 /* Allocate buffer in LINE_MAX increments */ 184 buf_max += 2048; 185 if((buf = realloc (buf, buf_max)) == NULL) { 186 err (1, NULL); 187 /* NOTREACHED */ 188 } 189 } 190 buf[indx++] = ch; 191 } 192 193 if (indx != 0) 194 fwrite (buf, 1, indx, stdout); 195 } 196 197 /* 198 * calculate the column position 199 */ 200 static int 201 new_column_position (col, ch) 202 int col; 203 int ch; 204 { 205 if (!count_bytes) { 206 switch (ch) { 207 case '\b': 208 if (col > 0) 209 --col; 210 break; 211 case '\r': 212 col = 0; 213 break; 214 case '\t': 215 col = (col + 8) & ~7; 216 break; 217 default: 218 ++col; 219 break; 220 } 221 } else { 222 ++col; 223 } 224 225 return col; 226 } 227
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