1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2000 Sheldon Hearn <sheldonh@FreeBSD.org>.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 */
29
30static const char rcsid[] =
31    "$FreeBSD$";
32
33#include <sys/stat.h>
34
35#include <ctype.h>
36#include <err.h>
37#include <errno.h>
38#include <fcntl.h>
39#include <stdio.h>
40#include <stdlib.h>
41#include <unistd.h>
42
43#include <libutil.h>
44
45static void	usage(void);
46
47int
48main(int argc, char **argv)
49{
50	struct stat sb;
51	mode_t omode;
52	off_t oflow, rsize, sz, tsize, round;
53	uint64_t usz;
54	int ch, error, fd, oflags;
55	int no_create;
56	int do_relative;
57	int do_round;
58	int do_refer;
59	int got_size;
60	char *fname, *rname;
61
62	fd = -1;
63	rsize = tsize = sz = 0;
64	no_create = do_relative = do_round = do_refer = got_size = 0;
65	error = 0;
66	rname = NULL;
67	while ((ch = getopt(argc, argv, "cr:s:")) != -1)
68		switch (ch) {
69		case 'c':
70			no_create = 1;
71			break;
72		case 'r':
73			do_refer = 1;
74			rname = optarg;
75			break;
76		case 's':
77			if (*optarg == '+' || *optarg == '-') {
78				do_relative = 1;
79			} else if (*optarg == '%' || *optarg == '/') {
80				do_round = 1;
81			}
82			if (expand_number(do_relative || do_round ?
83			    optarg + 1 : optarg,
84			    &usz) == -1 || (off_t)usz < 0)
85				errx(EXIT_FAILURE,
86				    "invalid size argument `%s'", optarg);
87
88			sz = (*optarg == '-' || *optarg == '/') ?
89				-(off_t)usz : (off_t)usz;
90			got_size = 1;
91			break;
92		default:
93			usage();
94			/* NOTREACHED */
95		}
96
97	argv += optind;
98	argc -= optind;
99
100	/*
101	 * Exactly one of do_refer or got_size must be specified.  Since
102	 * do_relative implies got_size, do_relative and do_refer are
103	 * also mutually exclusive.  See usage() for allowed invocations.
104	 */
105	if (do_refer + got_size != 1 || argc < 1)
106		usage();
107	if (do_refer) {
108		if (stat(rname, &sb) == -1)
109			err(EXIT_FAILURE, "%s", rname);
110		tsize = sb.st_size;
111	} else if (do_relative || do_round)
112		rsize = sz;
113	else
114		tsize = sz;
115
116	if (no_create)
117		oflags = O_WRONLY;
118	else
119		oflags = O_WRONLY | O_CREAT;
120	omode = S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH;
121
122	while ((fname = *argv++) != NULL) {
123		if (fd != -1)
124			close(fd);
125		if ((fd = open(fname, oflags, omode)) == -1) {
126			if (errno != ENOENT) {
127				warn("%s", fname);
128				error++;
129			}
130			continue;
131		}
132		if (do_relative) {
133			if (fstat(fd, &sb) == -1) {
134				warn("%s", fname);
135				error++;
136				continue;
137			}
138			oflow = sb.st_size + rsize;
139			if (oflow < (sb.st_size + rsize)) {
140				errno = EFBIG;
141				warn("%s", fname);
142				error++;
143				continue;
144			}
145			tsize = oflow;
146		}
147		if (do_round) {
148			if (fstat(fd, &sb) == -1) {
149				warn("%s", fname);
150				error++;
151				continue;
152			}
153			sz = rsize;
154			if (sz < 0)
155				sz = -sz;
156			if (sb.st_size % sz) {
157				round = sb.st_size / sz;
158				if (round != sz && rsize < 0)
159					round--;
160				else if (rsize > 0)
161					round++;
162				tsize = (round < 0 ? 0 : round) * sz;
163			} else
164				tsize = sb.st_size;
165		}
166		if (tsize < 0)
167			tsize = 0;
168
169		if (ftruncate(fd, tsize) == -1) {
170			warn("%s", fname);
171			error++;
172			continue;
173		}
174	}
175	if (fd != -1)
176		close(fd);
177
178	return error ? EXIT_FAILURE : EXIT_SUCCESS;
179}
180
181static void
182usage(void)
183{
184	fprintf(stderr, "%s\n%s\n",
185	    "usage: truncate [-c] -s [+|-|%|/]size[K|k|M|m|G|g|T|t] file ...",
186	    "       truncate [-c] -r rfile file ...");
187	exit(EXIT_FAILURE);
188}
189