xref: /freebsd/usr.bin/truncate/truncate.c (revision fc96358cdd560beb65578d169c1aefd39d0c54a2)
1614595dcSXin LI /*-
26b88e76bSSheldon Hearn  * Copyright (c) 2000 Sheldon Hearn <sheldonh@FreeBSD.org>.
36b88e76bSSheldon Hearn  * All rights reserved.
4edeb84a1SSheldon Hearn  *
5edeb84a1SSheldon Hearn  * Redistribution and use in source and binary forms, with or without
6edeb84a1SSheldon Hearn  * modification, are permitted provided that the following conditions
7edeb84a1SSheldon Hearn  * are met:
8edeb84a1SSheldon Hearn  * 1. Redistributions of source code must retain the above copyright
9edeb84a1SSheldon Hearn  *    notice, this list of conditions and the following disclaimer.
10edeb84a1SSheldon Hearn  * 2. Redistributions in binary form must reproduce the above copyright
11edeb84a1SSheldon Hearn  *    notice, this list of conditions and the following disclaimer in the
12edeb84a1SSheldon Hearn  *    documentation and/or other materials provided with the distribution.
13edeb84a1SSheldon Hearn  *
14edeb84a1SSheldon Hearn  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15edeb84a1SSheldon Hearn  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16edeb84a1SSheldon Hearn  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17edeb84a1SSheldon Hearn  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18edeb84a1SSheldon Hearn  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19edeb84a1SSheldon Hearn  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20edeb84a1SSheldon Hearn  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21edeb84a1SSheldon Hearn  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22edeb84a1SSheldon Hearn  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23edeb84a1SSheldon Hearn  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24edeb84a1SSheldon Hearn  * SUCH DAMAGE.
25edeb84a1SSheldon Hearn  *
26edeb84a1SSheldon Hearn  */
27edeb84a1SSheldon Hearn 
286b88e76bSSheldon Hearn #ifndef lint
296b88e76bSSheldon Hearn static const char rcsid[] =
306b88e76bSSheldon Hearn     "$FreeBSD$";
316b88e76bSSheldon Hearn #endif
326b88e76bSSheldon Hearn 
33edeb84a1SSheldon Hearn #include <sys/stat.h>
34edeb84a1SSheldon Hearn 
35edeb84a1SSheldon Hearn #include <ctype.h>
36edeb84a1SSheldon Hearn #include <err.h>
37edeb84a1SSheldon Hearn #include <errno.h>
38edeb84a1SSheldon Hearn #include <fcntl.h>
39edeb84a1SSheldon Hearn #include <stdio.h>
40edeb84a1SSheldon Hearn #include <stdlib.h>
41edeb84a1SSheldon Hearn #include <unistd.h>
42edeb84a1SSheldon Hearn 
4332bdc2b6SMaxim Sobolev #include <libutil.h>
4432bdc2b6SMaxim Sobolev 
453f330d7dSWarner Losh static void	usage(void);
46edeb84a1SSheldon Hearn 
47edeb84a1SSheldon Hearn static int	no_create;
48edeb84a1SSheldon Hearn static int	do_relative;
49edeb84a1SSheldon Hearn static int	do_refer;
50edeb84a1SSheldon Hearn static int	got_size;
51edeb84a1SSheldon Hearn 
52edeb84a1SSheldon Hearn int
53edeb84a1SSheldon Hearn main(int argc, char **argv)
54edeb84a1SSheldon Hearn {
55edeb84a1SSheldon Hearn 	struct stat	sb;
56edeb84a1SSheldon Hearn 	mode_t	omode;
57*fc96358cSJilles Tjoelker 	off_t	oflow, rsize, sz, tsize;
58*fc96358cSJilles Tjoelker 	uint64_t usz;
59edeb84a1SSheldon Hearn 	int	ch, error, fd, oflags;
60edeb84a1SSheldon Hearn 	char   *fname, *rname;
61edeb84a1SSheldon Hearn 
62d59e8ae8SColin Percival 	fd = -1;
63614595dcSXin LI 	rsize = tsize = sz = 0;
64edeb84a1SSheldon Hearn 	error = 0;
65b86e825aSSheldon Hearn 	rname = NULL;
66edeb84a1SSheldon Hearn 	while ((ch = getopt(argc, argv, "cr:s:")) != -1)
67edeb84a1SSheldon Hearn 		switch (ch) {
68edeb84a1SSheldon Hearn 		case 'c':
69b86e825aSSheldon Hearn 			no_create = 1;
70edeb84a1SSheldon Hearn 			break;
71edeb84a1SSheldon Hearn 		case 'r':
72b86e825aSSheldon Hearn 			do_refer = 1;
73edeb84a1SSheldon Hearn 			rname = optarg;
74edeb84a1SSheldon Hearn 			break;
75edeb84a1SSheldon Hearn 		case 's':
76*fc96358cSJilles Tjoelker 			do_relative = *optarg == '+' || *optarg == '-';
77*fc96358cSJilles Tjoelker 			if (expand_number(do_relative ? optarg + 1 : optarg,
78*fc96358cSJilles Tjoelker 			    &usz) == -1 || (off_t)usz < 0)
79edeb84a1SSheldon Hearn 				errx(EXIT_FAILURE,
80edeb84a1SSheldon Hearn 				    "invalid size argument `%s'", optarg);
81*fc96358cSJilles Tjoelker 
82*fc96358cSJilles Tjoelker 			sz = (*optarg == '-') ? -(off_t)usz : (off_t)usz;
83b86e825aSSheldon Hearn 			got_size = 1;
84edeb84a1SSheldon Hearn 			break;
85edeb84a1SSheldon Hearn 		default:
86edeb84a1SSheldon Hearn 			usage();
87edeb84a1SSheldon Hearn 			/* NOTREACHED */
88edeb84a1SSheldon Hearn 		}
89edeb84a1SSheldon Hearn 
90edeb84a1SSheldon Hearn 	argv += optind;
91edeb84a1SSheldon Hearn 	argc -= optind;
92edeb84a1SSheldon Hearn 
93edeb84a1SSheldon Hearn 	/*
94edeb84a1SSheldon Hearn 	 * Exactly one of do_refer or got_size must be specified.  Since
95edeb84a1SSheldon Hearn 	 * do_relative implies got_size, do_relative and do_refer are
96edeb84a1SSheldon Hearn 	 * also mutually exclusive.  See usage() for allowed invocations.
97edeb84a1SSheldon Hearn 	 */
98b86e825aSSheldon Hearn 	if (do_refer + got_size != 1 || argc < 1)
99edeb84a1SSheldon Hearn 		usage();
100edeb84a1SSheldon Hearn 	if (do_refer) {
101edeb84a1SSheldon Hearn 		if (stat(rname, &sb) == -1)
102edeb84a1SSheldon Hearn 			err(EXIT_FAILURE, "%s", rname);
103edeb84a1SSheldon Hearn 		tsize = sb.st_size;
104b86e825aSSheldon Hearn 	} else if (do_relative)
105edeb84a1SSheldon Hearn 		rsize = sz;
106edeb84a1SSheldon Hearn 	else
107edeb84a1SSheldon Hearn 		tsize = sz;
108edeb84a1SSheldon Hearn 
109edeb84a1SSheldon Hearn 	if (no_create)
110edeb84a1SSheldon Hearn 		oflags = O_WRONLY;
111edeb84a1SSheldon Hearn 	else
112edeb84a1SSheldon Hearn 		oflags = O_WRONLY | O_CREAT;
113edeb84a1SSheldon Hearn 	omode = S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH;
114edeb84a1SSheldon Hearn 
115edeb84a1SSheldon Hearn 	while ((fname = *argv++) != NULL) {
116a39846b5SMaxim Konovalov 		if (fd != -1)
117a39846b5SMaxim Konovalov 			close(fd);
118edeb84a1SSheldon Hearn 		if ((fd = open(fname, oflags, omode)) == -1) {
119edeb84a1SSheldon Hearn 			if (errno != ENOENT) {
120edeb84a1SSheldon Hearn 				warn("%s", fname);
121edeb84a1SSheldon Hearn 				error++;
122edeb84a1SSheldon Hearn 			}
123edeb84a1SSheldon Hearn 			continue;
124edeb84a1SSheldon Hearn 		}
125edeb84a1SSheldon Hearn 		if (do_relative) {
126edeb84a1SSheldon Hearn 			if (fstat(fd, &sb) == -1) {
127edeb84a1SSheldon Hearn 				warn("%s", fname);
128edeb84a1SSheldon Hearn 				error++;
129edeb84a1SSheldon Hearn 				continue;
130edeb84a1SSheldon Hearn 			}
131edeb84a1SSheldon Hearn 			oflow = sb.st_size + rsize;
132edeb84a1SSheldon Hearn 			if (oflow < (sb.st_size + rsize)) {
133edeb84a1SSheldon Hearn 				errno = EFBIG;
134edeb84a1SSheldon Hearn 				warn("%s", fname);
135edeb84a1SSheldon Hearn 				error++;
136edeb84a1SSheldon Hearn 				continue;
137edeb84a1SSheldon Hearn 			}
138edeb84a1SSheldon Hearn 			tsize = oflow;
139edeb84a1SSheldon Hearn 		}
140edeb84a1SSheldon Hearn 		if (tsize < 0)
141edeb84a1SSheldon Hearn 			tsize = 0;
142edeb84a1SSheldon Hearn 
143edeb84a1SSheldon Hearn 		if (ftruncate(fd, tsize) == -1) {
144edeb84a1SSheldon Hearn 			warn("%s", fname);
145edeb84a1SSheldon Hearn 			error++;
146edeb84a1SSheldon Hearn 			continue;
147edeb84a1SSheldon Hearn 		}
148edeb84a1SSheldon Hearn 	}
149a39846b5SMaxim Konovalov 	if (fd != -1)
150a39846b5SMaxim Konovalov 		close(fd);
151edeb84a1SSheldon Hearn 
152edeb84a1SSheldon Hearn 	return error ? EXIT_FAILURE : EXIT_SUCCESS;
153edeb84a1SSheldon Hearn }
154edeb84a1SSheldon Hearn 
155edeb84a1SSheldon Hearn static void
156edeb84a1SSheldon Hearn usage(void)
157edeb84a1SSheldon Hearn {
158edeb84a1SSheldon Hearn 	fprintf(stderr, "%s\n%s\n",
1590033dba8SCeri Davies 	    "usage: truncate [-c] -s [+|-]size[K|k|M|m|G|g|T|t] file ...",
160edeb84a1SSheldon Hearn 	    "       truncate [-c] -r rfile file ...");
161edeb84a1SSheldon Hearn 	exit(EXIT_FAILURE);
162edeb84a1SSheldon Hearn }
163