freebsd-dev/usr.bin/fold/fold.c
2002-05-25 03:04:28 +00:00

223 lines
5.3 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 <ctype.h>
#include <err.h>
#include <limits.h>
#include <locale.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#define DEFLINEWIDTH 80
void fold(int);
static int newpos(int, int);
static void usage(void);
int bflag; /* Count bytes, not columns */
int sflag; /* Split on word boundaries */
int
main(argc, argv)
int argc;
char **argv;
{
register int ch;
int rval, width;
char *p;
(void) setlocale(LC_CTYPE, "");
width = -1;
while ((ch = getopt(argc, argv, "0123456789bsw:")) != -1)
switch (ch) {
case 'b':
bflag = 1;
break;
case 's':
sflag = 1;
break;
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;
rval = 0;
if (!*argv)
fold(width);
else for (; *argv; ++argv)
if (!freopen(*argv, "r", stdin)) {
warn("%s", *argv);
rval = 1;
} else
fold(width);
exit(rval);
}
static void
usage()
{
(void)fprintf(stderr, "usage: fold [-bs] [-w width] [file ...]\n");
exit(1);
}
/*
* Fold the contents of standard input to fit within WIDTH columns (or bytes)
* and write to standard output.
*
* If sflag is set, split the line at the last space character on the line.
* This flag necessitates storing the line in a buffer until the current
* column > width, or a newline or EOF is read.
*
* The buffer can grow larger than WIDTH due to backspaces and carriage
* returns embedded in the input stream.
*/
void
fold(width)
register int width;
{
static char *buf;
static int buf_max;
int ch, col, i, indx, space;
col = indx = 0;
while ((ch = getchar()) != EOF) {
if (ch == '\n') {
if (indx != 0)
fwrite(buf, 1, indx, stdout);
putchar('\n');
col = indx = 0;
continue;
}
if ((col = newpos(col, ch)) > width) {
if (sflag) {
i = indx;
while (--i >= 0 && !isblank((unsigned char)buf[i]))
;
space = i;
}
if (sflag && space != -1) {
space++;
fwrite(buf, 1, space, stdout);
memmove(buf, buf + space, indx - space);
indx -= space;
col = 0;
for (i = 0; i < indx; i++)
col = newpos(col, buf[i]);
} else {
fwrite(buf, 1, indx, stdout);
col = indx = 0;
}
putchar('\n');
col = newpos(col, ch);
}
if (indx + 1 > buf_max) {
buf_max += LINE_MAX;
if ((buf = realloc(buf, buf_max)) == NULL)
err(1, "realloc()");
}
buf[indx++] = ch;
}
if (indx != 0)
fwrite(buf, 1, indx, stdout);
}
/*
* Update the current column position for a character.
*/
static int
newpos(col, ch)
int col, ch;
{
if (bflag)
++col;
else
switch (ch) {
case '\b':
if (col > 0)
--col;
break;
case '\r':
col = 0;
break;
case '\t':
col = (col + 8) & ~7;
break;
default:
++col;
break;
}
return (col);
}