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 * %sccs.include.redist.c% 9 */ 10 11 #ifndef lint 12 static char copyright[] = 13 "@(#) Copyright (c) 1990, 1993\n\ 14 The Regents of the University of California. All rights reserved.\n"; 15 #endif /* not lint */ 16 17 #ifndef lint 18 static char sccsid[] = "@(#)fold.c 8.1 (Berkeley) 06/06/93"; 19 #endif /* not lint */ 20 21 #include <stdio.h> 22 #include <string.h> 23 24 #define DEFLINEWIDTH 80 25 26 main(argc, argv) 27 int argc; 28 char **argv; 29 { 30 extern int errno, optind; 31 extern char *optarg; 32 register int ch; 33 int width; 34 char *p; 35 36 width = -1; 37 while ((ch = getopt(argc, argv, "0123456789w:")) != EOF) 38 switch (ch) { 39 case 'w': 40 if ((width = atoi(optarg)) <= 0) { 41 (void)fprintf(stderr, 42 "fold: illegal width value.\n"); 43 exit(1); 44 } 45 break; 46 case '0': case '1': case '2': case '3': case '4': 47 case '5': case '6': case '7': case '8': case '9': 48 if (width == -1) { 49 p = argv[optind - 1]; 50 if (p[0] == '-' && p[1] == ch && !p[2]) 51 width = atoi(++p); 52 else 53 width = atoi(argv[optind] + 1); 54 } 55 break; 56 default: 57 (void)fprintf(stderr, 58 "usage: fold [-w width] [file ...]\n"); 59 exit(1); 60 } 61 argv += optind; 62 argc -= optind; 63 64 if (width == -1) 65 width = DEFLINEWIDTH; 66 if (!*argv) 67 fold(width); 68 else for (; *argv; ++argv) 69 if (!freopen(*argv, "r", stdin)) { 70 (void)fprintf(stderr, 71 "fold: %s: %s\n", *argv, strerror(errno)); 72 exit(1); 73 } else 74 fold(width); 75 exit(0); 76 } 77 78 fold(width) 79 register int width; 80 { 81 register int ch, col, new; 82 83 for (col = 0;;) { 84 switch (ch = getchar()) { 85 case EOF: 86 return; 87 case '\b': 88 new = col ? col - 1 : 0; 89 break; 90 case '\n': 91 case '\r': 92 new = 0; 93 break; 94 case '\t': 95 new = (col + 8) & ~7; 96 break; 97 default: 98 new = col + 1; 99 break; 100 } 101 102 if (new > width) { 103 putchar('\n'); 104 col = 0; 105 } 106 putchar(ch); 107 108 switch (ch) { 109 case '\b': 110 if (col > 0) 111 --col; 112 break; 113 case '\n': 114 case '\r': 115 col = 0; 116 break; 117 case '\t': 118 col += 8; 119 col &= ~7; 120 break; 121 default: 122 ++col; 123 break; 124 } 125 } 126 } 127