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 30 static 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 45 static void usage(void); 46 47 int 48 main(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 } 180 181 static void 182 usage(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