freebsd-dev/usr.bin/fold/fold.c
2002-03-22 01:22:50 +00:00

164 lines
3.8 KiB
C

/*-
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Kevin Ruddy.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef lint
static const char copyright[] =
"@(#) Copyright (c) 1990, 1993\n\
The Regents of the University of California. All rights reserved.\n";
#endif /* not lint */
#ifndef lint
#if 0
static char sccsid[] = "@(#)fold.c 8.1 (Berkeley) 6/6/93";
#endif
#endif /* not lint */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#define DEFLINEWIDTH 80
void fold(int);
static void usage(void);
int
main(argc, argv)
int argc;
char **argv;
{
register int ch;
int width;
char *p;
width = -1;
while ((ch = getopt(argc, argv, "0123456789w:")) != -1)
switch (ch) {
case 'w':
if ((width = atoi(optarg)) <= 0) {
errx(1, "illegal width value");
}
break;
case '0': case '1': case '2': case '3': case '4':
case '5': case '6': case '7': case '8': case '9':
if (width == -1) {
p = argv[optind - 1];
if (p[0] == '-' && p[1] == ch && !p[2])
width = atoi(++p);
else
width = atoi(argv[optind] + 1);
}
break;
default:
usage();
}
argv += optind;
argc -= optind;
if (width == -1)
width = DEFLINEWIDTH;
if (!*argv)
fold(width);
else for (; *argv; ++argv)
if (!freopen(*argv, "r", stdin)) {
err(1, "%s", *argv);
} else
fold(width);
exit(0);
}
static void
usage()
{
(void)fprintf(stderr, "usage: fold [-w width] [file ...]\n");
exit(1);
}
void
fold(width)
register int width;
{
register int ch, col, new;
for (col = 0;;) {
switch (ch = getchar()) {
case EOF:
return;
case '\b':
new = col ? col - 1 : 0;
break;
case '\n':
case '\r':
new = 0;
break;
case '\t':
new = (col + 8) & ~7;
break;
default:
new = col + 1;
break;
}
if (new > width) {
putchar('\n');
col = 0;
}
putchar(ch);
switch (ch) {
case '\b':
if (col > 0)
--col;
break;
case '\n':
case '\r':
col = 0;
break;
case '\t':
col += 8;
col &= ~7;
break;
default:
++col;
break;
}
}
}