xref: /freebsd/usr.bin/fold/fold.c (revision 9b50d9027575220cb6dd09b3e62f03f511e908b8)
19b50d902SRodney W. Grimes /*-
29b50d902SRodney W. Grimes  * Copyright (c) 1990, 1993
39b50d902SRodney W. Grimes  *	The Regents of the University of California.  All rights reserved.
49b50d902SRodney W. Grimes  *
59b50d902SRodney W. Grimes  * This code is derived from software contributed to Berkeley by
69b50d902SRodney W. Grimes  * Kevin Ruddy.
79b50d902SRodney W. Grimes  *
89b50d902SRodney W. Grimes  * Redistribution and use in source and binary forms, with or without
99b50d902SRodney W. Grimes  * modification, are permitted provided that the following conditions
109b50d902SRodney W. Grimes  * are met:
119b50d902SRodney W. Grimes  * 1. Redistributions of source code must retain the above copyright
129b50d902SRodney W. Grimes  *    notice, this list of conditions and the following disclaimer.
139b50d902SRodney W. Grimes  * 2. Redistributions in binary form must reproduce the above copyright
149b50d902SRodney W. Grimes  *    notice, this list of conditions and the following disclaimer in the
159b50d902SRodney W. Grimes  *    documentation and/or other materials provided with the distribution.
169b50d902SRodney W. Grimes  * 3. All advertising materials mentioning features or use of this software
179b50d902SRodney W. Grimes  *    must display the following acknowledgement:
189b50d902SRodney W. Grimes  *	This product includes software developed by the University of
199b50d902SRodney W. Grimes  *	California, Berkeley and its contributors.
209b50d902SRodney W. Grimes  * 4. Neither the name of the University nor the names of its contributors
219b50d902SRodney W. Grimes  *    may be used to endorse or promote products derived from this software
229b50d902SRodney W. Grimes  *    without specific prior written permission.
239b50d902SRodney W. Grimes  *
249b50d902SRodney W. Grimes  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
259b50d902SRodney W. Grimes  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
269b50d902SRodney W. Grimes  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
279b50d902SRodney W. Grimes  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
289b50d902SRodney W. Grimes  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
299b50d902SRodney W. Grimes  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
309b50d902SRodney W. Grimes  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
319b50d902SRodney W. Grimes  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
329b50d902SRodney W. Grimes  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
339b50d902SRodney W. Grimes  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
349b50d902SRodney W. Grimes  * SUCH DAMAGE.
359b50d902SRodney W. Grimes  */
369b50d902SRodney W. Grimes 
379b50d902SRodney W. Grimes #ifndef lint
389b50d902SRodney W. Grimes static char copyright[] =
399b50d902SRodney W. Grimes "@(#) Copyright (c) 1990, 1993\n\
409b50d902SRodney W. Grimes 	The Regents of the University of California.  All rights reserved.\n";
419b50d902SRodney W. Grimes #endif /* not lint */
429b50d902SRodney W. Grimes 
439b50d902SRodney W. Grimes #ifndef lint
449b50d902SRodney W. Grimes static char sccsid[] = "@(#)fold.c	8.1 (Berkeley) 6/6/93";
459b50d902SRodney W. Grimes #endif /* not lint */
469b50d902SRodney W. Grimes 
479b50d902SRodney W. Grimes #include <stdio.h>
489b50d902SRodney W. Grimes #include <string.h>
499b50d902SRodney W. Grimes 
509b50d902SRodney W. Grimes #define	DEFLINEWIDTH	80
519b50d902SRodney W. Grimes 
529b50d902SRodney W. Grimes main(argc, argv)
539b50d902SRodney W. Grimes 	int argc;
549b50d902SRodney W. Grimes 	char **argv;
559b50d902SRodney W. Grimes {
569b50d902SRodney W. Grimes 	extern int errno, optind;
579b50d902SRodney W. Grimes 	extern char *optarg;
589b50d902SRodney W. Grimes 	register int ch;
599b50d902SRodney W. Grimes 	int width;
609b50d902SRodney W. Grimes 	char *p;
619b50d902SRodney W. Grimes 
629b50d902SRodney W. Grimes 	width = -1;
639b50d902SRodney W. Grimes 	while ((ch = getopt(argc, argv, "0123456789w:")) != EOF)
649b50d902SRodney W. Grimes 		switch (ch) {
659b50d902SRodney W. Grimes 		case 'w':
669b50d902SRodney W. Grimes 			if ((width = atoi(optarg)) <= 0) {
679b50d902SRodney W. Grimes 				(void)fprintf(stderr,
689b50d902SRodney W. Grimes 				    "fold: illegal width value.\n");
699b50d902SRodney W. Grimes 				exit(1);
709b50d902SRodney W. Grimes 			}
719b50d902SRodney W. Grimes 			break;
729b50d902SRodney W. Grimes 		case '0': case '1': case '2': case '3': case '4':
739b50d902SRodney W. Grimes 		case '5': case '6': case '7': case '8': case '9':
749b50d902SRodney W. Grimes 			if (width == -1) {
759b50d902SRodney W. Grimes 				p = argv[optind - 1];
769b50d902SRodney W. Grimes 				if (p[0] == '-' && p[1] == ch && !p[2])
779b50d902SRodney W. Grimes 					width = atoi(++p);
789b50d902SRodney W. Grimes 				else
799b50d902SRodney W. Grimes 					width = atoi(argv[optind] + 1);
809b50d902SRodney W. Grimes 			}
819b50d902SRodney W. Grimes 			break;
829b50d902SRodney W. Grimes 		default:
839b50d902SRodney W. Grimes 			(void)fprintf(stderr,
849b50d902SRodney W. Grimes 			    "usage: fold [-w width] [file ...]\n");
859b50d902SRodney W. Grimes 			exit(1);
869b50d902SRodney W. Grimes 		}
879b50d902SRodney W. Grimes 	argv += optind;
889b50d902SRodney W. Grimes 	argc -= optind;
899b50d902SRodney W. Grimes 
909b50d902SRodney W. Grimes 	if (width == -1)
919b50d902SRodney W. Grimes 		width = DEFLINEWIDTH;
929b50d902SRodney W. Grimes 	if (!*argv)
939b50d902SRodney W. Grimes 		fold(width);
949b50d902SRodney W. Grimes 	else for (; *argv; ++argv)
959b50d902SRodney W. Grimes 		if (!freopen(*argv, "r", stdin)) {
969b50d902SRodney W. Grimes 			(void)fprintf(stderr,
979b50d902SRodney W. Grimes 			    "fold: %s: %s\n", *argv, strerror(errno));
989b50d902SRodney W. Grimes 			exit(1);
999b50d902SRodney W. Grimes 		} else
1009b50d902SRodney W. Grimes 			fold(width);
1019b50d902SRodney W. Grimes 	exit(0);
1029b50d902SRodney W. Grimes }
1039b50d902SRodney W. Grimes 
1049b50d902SRodney W. Grimes fold(width)
1059b50d902SRodney W. Grimes 	register int width;
1069b50d902SRodney W. Grimes {
1079b50d902SRodney W. Grimes 	register int ch, col, new;
1089b50d902SRodney W. Grimes 
1099b50d902SRodney W. Grimes 	for (col = 0;;) {
1109b50d902SRodney W. Grimes 		switch (ch = getchar()) {
1119b50d902SRodney W. Grimes 		case EOF:
1129b50d902SRodney W. Grimes 			return;
1139b50d902SRodney W. Grimes 		case '\b':
1149b50d902SRodney W. Grimes 			new = col ? col - 1 : 0;
1159b50d902SRodney W. Grimes 			break;
1169b50d902SRodney W. Grimes 		case '\n':
1179b50d902SRodney W. Grimes 		case '\r':
1189b50d902SRodney W. Grimes 			new = 0;
1199b50d902SRodney W. Grimes 			break;
1209b50d902SRodney W. Grimes 		case '\t':
1219b50d902SRodney W. Grimes 			new = (col + 8) & ~7;
1229b50d902SRodney W. Grimes 			break;
1239b50d902SRodney W. Grimes 		default:
1249b50d902SRodney W. Grimes 			new = col + 1;
1259b50d902SRodney W. Grimes 			break;
1269b50d902SRodney W. Grimes 		}
1279b50d902SRodney W. Grimes 
1289b50d902SRodney W. Grimes 		if (new > width) {
1299b50d902SRodney W. Grimes 			putchar('\n');
1309b50d902SRodney W. Grimes 			col = 0;
1319b50d902SRodney W. Grimes 		}
1329b50d902SRodney W. Grimes 		putchar(ch);
1339b50d902SRodney W. Grimes 
1349b50d902SRodney W. Grimes 		switch (ch) {
1359b50d902SRodney W. Grimes 		case '\b':
1369b50d902SRodney W. Grimes 			if (col > 0)
1379b50d902SRodney W. Grimes 				--col;
1389b50d902SRodney W. Grimes 			break;
1399b50d902SRodney W. Grimes 		case '\n':
1409b50d902SRodney W. Grimes 		case '\r':
1419b50d902SRodney W. Grimes 			col = 0;
1429b50d902SRodney W. Grimes 			break;
1439b50d902SRodney W. Grimes 		case '\t':
1449b50d902SRodney W. Grimes 			col += 8;
1459b50d902SRodney W. Grimes 			col &= ~7;
1469b50d902SRodney W. Grimes 			break;
1479b50d902SRodney W. Grimes 		default:
1489b50d902SRodney W. Grimes 			++col;
1499b50d902SRodney W. Grimes 			break;
1509b50d902SRodney W. Grimes 		}
1519b50d902SRodney W. Grimes 	}
1529b50d902SRodney W. Grimes }
153