2 * Copyright (c) 2000 Sheldon Hearn <sheldonh@FreeBSD.org>.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * $FreeBSD: src/usr.bin/truncate/truncate.c,v 1.6.2.1 2000/08/04 08:05:52 sheldonh Exp $
27 * $DragonFly: src/usr.bin/truncate/truncate.c,v 1.3 2003/10/04 20:36:53 hmp Exp $
40 static off_t parselength(char *, off_t *);
41 static void usage(void);
44 static int do_relative;
49 main(int argc, char **argv)
53 off_t oflow, rsize, sz, tsize;
54 int ch, error, fd, oflags;
60 while ((ch = getopt(argc, argv, "cr:s:")) != -1)
70 if (parselength(optarg, &sz) == -1)
72 "invalid size argument `%s'", optarg);
73 if (*optarg == '+' || *optarg == '-')
86 * Exactly one of do_refer or got_size must be specified. Since
87 * do_relative implies got_size, do_relative and do_refer are
88 * also mutually exclusive. See usage() for allowed invocations.
90 if (do_refer + got_size != 1 || argc < 1)
93 if (stat(rname, &sb) == -1)
94 err(EXIT_FAILURE, "%s", rname);
96 } else if (do_relative)
104 oflags = O_WRONLY | O_CREAT;
105 omode = S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH;
107 while ((fname = *argv++) != NULL) {
108 if ((fd = open(fname, oflags, omode)) == -1) {
109 if (errno != ENOENT) {
116 if (fstat(fd, &sb) == -1) {
121 oflow = sb.st_size + rsize;
122 if (oflow < (sb.st_size + rsize)) {
133 if (ftruncate(fd, tsize) == -1) {
142 return error ? EXIT_FAILURE : EXIT_SUCCESS;
146 * Return the numeric value of a string given in the form [+-][0-9]+[GMK]
147 * or -1 on format error or overflow.
150 parselength(char *ls, off_t *sz)
165 #define ASSIGN_CHK_OFLOW(x, y) if (x < y) return -1; y = x
167 * Calculate the value of the decimal digit string, failing
170 while (isdigit(*ls)) {
171 oflow = length * 10 + *ls++ - '0';
172 ASSIGN_CHK_OFLOW(oflow, length);
177 oflow = length * 1024;
178 ASSIGN_CHK_OFLOW(oflow, length);
180 oflow = length * 1024;
181 ASSIGN_CHK_OFLOW(oflow, length);
185 oflow = length * 1024;
186 ASSIGN_CHK_OFLOW(oflow, length);
193 *sz = length * lsign;
200 fprintf(stderr, "%s\n%s\n",
201 "usage: truncate [-c] -s [+|-]size[K|M|G] file ...",
202 " truncate [-c] -r rfile file ...");