1 /* 2 * Copyright (c) 2000 FreeBSD, Inc. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23 * SUCH DAMAGE. 24 * 25 * $FreeBSD$ 26 */ 27 28 #include <sys/stat.h> 29 #include <sys/types.h> 30 31 #include <ctype.h> 32 #include <err.h> 33 #include <errno.h> 34 #include <fcntl.h> 35 #include <limits.h> 36 #include <stdio.h> 37 #include <stdlib.h> 38 #include <unistd.h> 39 40 static off_t parselength __P((char *, off_t *)); 41 static void usage __P((void)); 42 43 static int no_create; 44 static int do_relative; 45 static int do_refer; 46 static int got_size; 47 48 int 49 main(int argc, char **argv) 50 { 51 struct stat sb; 52 mode_t omode; 53 off_t oflow, rsize, sz, tsize; 54 int ch, error, fd, oflags; 55 char *fname, *rname; 56 57 error = 0; 58 while ((ch = getopt(argc, argv, "cr:s:")) != -1) 59 switch (ch) { 60 case 'c': 61 no_create++; 62 break; 63 case 'r': 64 do_refer++; 65 rname = optarg; 66 break; 67 case 's': 68 if (parselength(optarg, &sz) == -1) 69 errx(EXIT_FAILURE, 70 "invalid size argument `%s'", optarg); 71 if (*optarg == '+' || *optarg == '-') 72 do_relative++; 73 got_size++; 74 break; 75 default: 76 usage(); 77 /* NOTREACHED */ 78 } 79 80 argv += optind; 81 argc -= optind; 82 83 /* 84 * Exactly one of do_refer or got_size must be specified. Since 85 * do_relative implies got_size, do_relative and do_refer are 86 * also mutually exclusive. See usage() for allowed invocations. 87 */ 88 if (!(do_refer || got_size) || (do_refer && got_size) || argc < 1) 89 usage(); 90 if (do_refer) { 91 if (stat(rname, &sb) == -1) 92 err(EXIT_FAILURE, "%s", rname); 93 tsize = sb.st_size; 94 } else if (got_size) { 95 if (do_relative) 96 rsize = sz; 97 else 98 tsize = sz; 99 } 100 101 if (no_create) 102 oflags = O_WRONLY; 103 else 104 oflags = O_WRONLY | O_CREAT; 105 omode = S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH; 106 107 while ((fname = *argv++) != NULL) { 108 if ((fd = open(fname, oflags, omode)) == -1) { 109 if (errno != ENOENT) { 110 warn("%s", fname); 111 error++; 112 } 113 continue; 114 } 115 if (do_relative) { 116 if (fstat(fd, &sb) == -1) { 117 warn("%s", fname); 118 error++; 119 continue; 120 } 121 oflow = sb.st_size + rsize; 122 if (oflow < (sb.st_size + rsize)) { 123 errno = EFBIG; 124 warn("%s", fname); 125 error++; 126 continue; 127 } 128 tsize = oflow; 129 } 130 if (tsize < 0) 131 tsize = 0; 132 133 if (ftruncate(fd, tsize) == -1) { 134 warn("%s", fname); 135 error++; 136 continue; 137 } 138 } 139 140 return error ? EXIT_FAILURE : EXIT_SUCCESS; 141 } 142 143 /* 144 * Return the numeric value of a string given in the form [+-][0-9]+[GMK] 145 * or -1 on format error or overflow. 146 */ 147 static off_t 148 parselength(char *ls, off_t *sz) 149 { 150 off_t length, oflow; 151 int lsign; 152 153 length = 0; 154 lsign = 1; 155 156 switch (*ls) { 157 case '-': 158 lsign = -1; 159 case '+': 160 ls++; 161 } 162 163 #define ASSIGN_CHK_OFLOW(x, y) if (x < y) return -1; y = x 164 /* 165 * Calculate the value of the decimal digit string, failing 166 * on overflow. 167 */ 168 while (isdigit(*ls)) { 169 oflow = length * 10 + *ls++ - '0'; 170 ASSIGN_CHK_OFLOW(oflow, length); 171 } 172 173 switch (*ls) { 174 case 'G': 175 oflow = length * 1024; 176 ASSIGN_CHK_OFLOW(oflow, length); 177 case 'M': 178 oflow = length * 1024; 179 ASSIGN_CHK_OFLOW(oflow, length); 180 case 'K': 181 if (ls[1] != '\0') 182 return -1; 183 oflow = length * 1024; 184 ASSIGN_CHK_OFLOW(oflow, length); 185 case '\0': 186 break; 187 default: 188 return -1; 189 } 190 191 *sz = length * lsign; 192 return 0; 193 } 194 195 static void 196 usage(void) 197 { 198 fprintf(stderr, "%s\n%s\n", 199 "usage: truncate [-c] -s [+|-]size[K|M|G] file ...", 200 " truncate [-c] -r rfile file ..."); 201 exit(EXIT_FAILURE); 202 } 203