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/* $OpenBSD: fold.c,v 1.15 2015/02/06 09:10:55 tedu Exp $ */
/* $NetBSD: fold.c,v 1.6 1995/09/01 01:42:44 jtc Exp $ */
/*-
* 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. 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.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <ctype.h>
#include <err.h>
#include <limits.h>
#define DEFLINEWIDTH 80
static void fold(unsigned int);
static unsigned int new_column_position(unsigned int, int);
static __dead void usage(void);
int count_bytes = 0;
int split_words = 0;
int
main(int argc, char *argv[])
{
int ch, lastch, newarg, prevoptind;
unsigned int width;
const char *errstr;
width = 0;
lastch = '\0';
prevoptind = 1;
newarg = 1;
while ((ch = getopt(argc, argv, "0123456789bsw:")) != -1) {
switch (ch) {
case 'b':
count_bytes = 1;
break;
case 's':
split_words = 1;
break;
case 'w':
width = strtonum(optarg, 1, UINT_MAX, &errstr);
if (errstr != NULL)
errx(1, "illegal width value, %s: %s", errstr,
optarg);
break;
case '0': case '1': case '2': case '3': case '4':
case '5': case '6': case '7': case '8': case '9':
if (newarg)
width = 0;
else if (!isdigit(lastch))
usage();
if (width > UINT_MAX / 10 - 1)
errx(1, "illegal width value, too large");
width = (width * 10) + (ch - '0');
if (width < 1)
errx(1, "illegal width value, too small");
break;
default:
usage();
}
lastch = ch;
newarg = optind != prevoptind;
prevoptind = optind;
}
argv += optind;
argc -= optind;
if (width == 0)
width = DEFLINEWIDTH;
if (!*argv)
fold(width);
else for (; *argv; ++argv)
if (!freopen(*argv, "r", stdin)) {
err(1, "%s", *argv);
/* NOTREACHED */
} else
fold(width);
exit(0);
}
/*
* Fold the contents of standard input to fit within WIDTH columns
* (or bytes) and write to standard output.
*
* If split_words 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.
*/
static void
fold(unsigned int width)
{
static char *buf = NULL;
static int buf_max = 0;
int ch;
unsigned int col, indx;
col = indx = 0;
while ((ch = getchar()) != EOF) {
if (ch == '\n') {
if (indx != 0)
fwrite(buf, 1, indx, stdout);
putchar('\n');
col = indx = 0;
continue;
}
col = new_column_position(col, ch);
if (col > width) {
unsigned int i, last_space;
if (split_words) {
for (i = 0, last_space = -1; i < indx; i++)
if(buf[i] == ' ')
last_space = i;
}
if (split_words && last_space != -1) {
last_space++;
fwrite(buf, 1, last_space, stdout);
memmove(buf, buf+last_space, indx-last_space);
indx -= last_space;
col = 0;
for (i = 0; i < indx; i++) {
col = new_column_position(col, buf[i]);
}
} else {
fwrite(buf, 1, indx, stdout);
col = indx = 0;
}
putchar('\n');
/* calculate the column position for the next line. */
col = new_column_position(col, ch);
}
if (indx + 1 > buf_max) {
int newmax = buf_max + 2048;
char *newbuf;
/* Allocate buffer in LINE_MAX increments */
if ((newbuf = realloc(buf, newmax)) == NULL) {
err(1, NULL);
/* NOTREACHED */
}
buf = newbuf;
buf_max = newmax;
}
buf[indx++] = ch;
}
if (indx != 0)
fwrite(buf, 1, indx, stdout);
}
/*
* calculate the column position
*/
static unsigned int
new_column_position(unsigned int col, int ch)
{
if (!count_bytes) {
switch (ch) {
case '\b':
if (col > 0)
--col;
break;
case '\r':
col = 0;
break;
case '\t':
col = (col + 8) & ~7;
break;
default:
++col;
break;
}
} else {
++col;
}
return col;
}
static __dead void
usage(void)
{
(void)fprintf(stderr, "usage: fold [-bs] [-w width] [file ...]\n");
exit(1);
}
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