203 lines
4.5 KiB
C
203 lines
4.5 KiB
C
/*
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* Copyright (c) 2000 FreeBSD, Inc. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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#include <sys/stat.h>
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#include <sys/types.h>
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#include <ctype.h>
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#include <err.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <limits.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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static off_t parselength __P((char *, off_t *));
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static void usage __P((void));
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static int no_create;
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static int do_relative;
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static int do_refer;
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static int got_size;
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int
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main(int argc, char **argv)
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{
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struct stat sb;
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mode_t omode;
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off_t oflow, rsize, sz, tsize;
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int ch, error, fd, oflags;
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char *fname, *rname;
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error = 0;
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while ((ch = getopt(argc, argv, "cr:s:")) != -1)
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switch (ch) {
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case 'c':
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no_create++;
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break;
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case 'r':
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do_refer++;
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rname = optarg;
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break;
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case 's':
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if (parselength(optarg, &sz) == -1)
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errx(EXIT_FAILURE,
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"invalid size argument `%s'", optarg);
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if (*optarg == '+' || *optarg == '-')
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do_relative++;
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got_size++;
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break;
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default:
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usage();
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/* NOTREACHED */
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}
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argv += optind;
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argc -= optind;
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/*
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* Exactly one of do_refer or got_size must be specified. Since
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* do_relative implies got_size, do_relative and do_refer are
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* also mutually exclusive. See usage() for allowed invocations.
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*/
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if (!(do_refer || got_size) || (do_refer && got_size) || argc < 1)
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usage();
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if (do_refer) {
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if (stat(rname, &sb) == -1)
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err(EXIT_FAILURE, "%s", rname);
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tsize = sb.st_size;
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} else if (got_size) {
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if (do_relative)
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rsize = sz;
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else
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tsize = sz;
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}
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if (no_create)
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oflags = O_WRONLY;
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else
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oflags = O_WRONLY | O_CREAT;
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omode = S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH;
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while ((fname = *argv++) != NULL) {
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if ((fd = open(fname, oflags, omode)) == -1) {
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if (errno != ENOENT) {
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warn("%s", fname);
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error++;
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}
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continue;
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}
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if (do_relative) {
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if (fstat(fd, &sb) == -1) {
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warn("%s", fname);
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error++;
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continue;
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}
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oflow = sb.st_size + rsize;
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if (oflow < (sb.st_size + rsize)) {
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errno = EFBIG;
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warn("%s", fname);
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error++;
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continue;
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}
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tsize = oflow;
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}
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if (tsize < 0)
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tsize = 0;
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if (ftruncate(fd, tsize) == -1) {
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warn("%s", fname);
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error++;
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continue;
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}
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}
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return error ? EXIT_FAILURE : EXIT_SUCCESS;
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}
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/*
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* Return the numeric value of a string given in the form [+-][0-9]+[GMK]
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* or -1 on format error or overflow.
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*/
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static off_t
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parselength(char *ls, off_t *sz)
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{
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off_t length, oflow;
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int lsign;
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length = 0;
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lsign = 1;
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switch (*ls) {
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case '-':
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lsign = -1;
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case '+':
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ls++;
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}
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#define ASSIGN_CHK_OFLOW(x, y) if (x < y) return -1; y = x
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/*
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* Calculate the value of the decimal digit string, failing
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* on overflow.
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*/
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while (isdigit(*ls)) {
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oflow = length * 10 + *ls++ - '0';
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ASSIGN_CHK_OFLOW(oflow, length);
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}
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switch (*ls) {
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case 'G':
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oflow = length * 1024;
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ASSIGN_CHK_OFLOW(oflow, length);
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case 'M':
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oflow = length * 1024;
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ASSIGN_CHK_OFLOW(oflow, length);
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case 'K':
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if (ls[1] != '\0')
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return -1;
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oflow = length * 1024;
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ASSIGN_CHK_OFLOW(oflow, length);
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case '\0':
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break;
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default:
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return -1;
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}
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*sz = length * lsign;
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return 0;
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}
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static void
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usage(void)
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{
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fprintf(stderr, "%s\n%s\n",
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"usage: truncate [-c] -s [+|-]size[K|M|G] file ...",
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" truncate [-c] -r rfile file ...");
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exit(EXIT_FAILURE);
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}
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