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/*
* Copyright (c) 2000 Sheldon Hearn <sheldonh@FreeBSD.org>.
* All rights reserved.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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 rcsid[] =
"$FreeBSD$";
#endif
#include <sys/stat.h>
#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
static off_t parselength(char *, off_t *);
static void usage(void);
static int no_create;
static int do_relative;
static int do_refer;
static int got_size;
int
main(int argc, char **argv)
{
struct stat sb;
mode_t omode;
off_t oflow, rsize, sz, tsize;
int ch, error, fd, oflags;
char *fname, *rname;
rsize = tsize = 0;
error = 0;
rname = NULL;
while ((ch = getopt(argc, argv, "cr:s:")) != -1)
switch (ch) {
case 'c':
no_create = 1;
break;
case 'r':
do_refer = 1;
rname = optarg;
break;
case 's':
if (parselength(optarg, &sz) == -1)
errx(EXIT_FAILURE,
"invalid size argument `%s'", optarg);
if (*optarg == '+' || *optarg == '-')
do_relative = 1;
got_size = 1;
break;
default:
usage();
/* NOTREACHED */
}
argv += optind;
argc -= optind;
/*
* Exactly one of do_refer or got_size must be specified. Since
* do_relative implies got_size, do_relative and do_refer are
* also mutually exclusive. See usage() for allowed invocations.
*/
if (do_refer + got_size != 1 || argc < 1)
usage();
if (do_refer) {
if (stat(rname, &sb) == -1)
err(EXIT_FAILURE, "%s", rname);
tsize = sb.st_size;
} else if (do_relative)
rsize = sz;
else
tsize = sz;
if (no_create)
oflags = O_WRONLY;
else
oflags = O_WRONLY | O_CREAT;
omode = S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH;
while ((fname = *argv++) != NULL) {
if ((fd = open(fname, oflags, omode)) == -1) {
if (errno != ENOENT) {
warn("%s", fname);
error++;
}
continue;
}
if (do_relative) {
if (fstat(fd, &sb) == -1) {
warn("%s", fname);
error++;
continue;
}
oflow = sb.st_size + rsize;
if (oflow < (sb.st_size + rsize)) {
errno = EFBIG;
warn("%s", fname);
error++;
continue;
}
tsize = oflow;
}
if (tsize < 0)
tsize = 0;
if (ftruncate(fd, tsize) == -1) {
warn("%s", fname);
error++;
continue;
}
close(fd);
}
return error ? EXIT_FAILURE : EXIT_SUCCESS;
}
/*
* Return the numeric value of a string given in the form [+-][0-9]+[GMK]
* or -1 on format error or overflow.
*/
static off_t
parselength(char *ls, off_t *sz)
{
off_t length, oflow;
int lsign;
length = 0;
lsign = 1;
switch (*ls) {
case '-':
lsign = -1;
case '+':
ls++;
}
#define ASSIGN_CHK_OFLOW(x, y) if (x < y) return -1; y = x
/*
* Calculate the value of the decimal digit string, failing
* on overflow.
*/
while (isdigit(*ls)) {
oflow = length * 10 + *ls++ - '0';
ASSIGN_CHK_OFLOW(oflow, length);
}
switch (*ls) {
case 'G':
oflow = length * 1024;
ASSIGN_CHK_OFLOW(oflow, length);
case 'M':
oflow = length * 1024;
ASSIGN_CHK_OFLOW(oflow, length);
case 'K':
if (ls[1] != '\0')
return -1;
oflow = length * 1024;
ASSIGN_CHK_OFLOW(oflow, length);
case '\0':
break;
default:
return -1;
}
*sz = length * lsign;
return 0;
}
static void
usage(void)
{
fprintf(stderr, "%s\n%s\n",
"usage: truncate [-c] -s [+|-]size[K|M|G] file ...",
" truncate [-c] -r rfile file ...");
exit(EXIT_FAILURE);
}
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