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 38 static 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 45 static char sccsid[] = "@(#)fold.c 8.1 (Berkeley) 6/6/93"; 46 #endif 47 #endif /* not lint */ 48 49 #include <sys/cdefs.h> 50 __FBSDID("$FreeBSD$"); 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 63 void fold(int); 64 static int newpos(int, int); 65 static void usage(void); 66 67 int bflag; /* Count bytes, not columns */ 68 int sflag; /* Split on word boundaries */ 69 70 int 71 main(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 } 122 123 static void 124 usage(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 */ 141 void 142 fold(int width) 143 { 144 static char *buf; 145 static int buf_max; 146 int ch, col, i, indx, space; 147 148 col = indx = 0; 149 while ((ch = getchar()) != EOF) { 150 if (ch == '\n') { 151 if (indx != 0) 152 fwrite(buf, 1, indx, stdout); 153 putchar('\n'); 154 col = indx = 0; 155 continue; 156 } 157 if ((col = newpos(col, ch)) > width) { 158 if (sflag) { 159 i = indx; 160 while (--i >= 0 && !isblank((unsigned char)buf[i])) 161 ; 162 space = i; 163 } 164 if (sflag && space != -1) { 165 space++; 166 fwrite(buf, 1, space, stdout); 167 memmove(buf, buf + space, indx - space); 168 indx -= space; 169 col = 0; 170 for (i = 0; i < indx; i++) 171 col = newpos(col, 172 (unsigned char)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 */ 195 static int 196 newpos(int col, int ch) 197 { 198 199 if (bflag) 200 ++col; 201 else 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 if (isprint(ch)) 215 ++col; 216 break; 217 } 218 219 return (col); 220 } 221