1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2021 Peter Holm <pho@FreeBSD.org> 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 #include <sys/param.h> 29 #include <sys/stat.h> 30 31 #include <err.h> 32 #include <errno.h> 33 #include <fcntl.h> 34 #include <stdio.h> 35 #include <stdlib.h> 36 #include <unistd.h> 37 38 int 39 main(int argc, char *argv[]) 40 { 41 struct stat st; 42 off_t data, hole, pos; 43 long mn; 44 intmax_t siz; 45 int fd, n; 46 char *name; 47 48 if (argc != 2) { 49 fprintf(stderr, "Usage: %s <file>\n", argv[0]); 50 exit(1); 51 } 52 53 name = argv[1]; 54 if ((fd = open(name, O_RDONLY)) == -1) 55 err(1, "open(%s)", name); 56 if (fstat(fd, &st)) 57 err(1, "fstat()"); 58 if ((mn = fpathconf(fd, _PC_MIN_HOLE_SIZE)) == -1) 59 err(1, "fpathconf()"); 60 fprintf(stderr, "Min hole size is %ld, file size is %jd.\n", 61 mn, (intmax_t)st.st_size); 62 n = 1; 63 pos = 0; 64 65 while (pos < st.st_size) { 66 hole = lseek(fd, pos, SEEK_HOLE); 67 if (hole == -1 && errno != ENXIO) 68 err(1, "lseek(SEEK_HOLE)"); 69 data = lseek(fd, pos, SEEK_DATA); 70 if (data == -1 && errno != ENXIO) 71 err(1, "lseek(SEEK_data)"); 72 73 if (hole >= 0 && data >= 0 && hole > data) { 74 siz = hole - data; 75 printf("data #%d @ %ld, size=%jd)\n", 76 n, (intmax_t)data, siz); 77 n++; 78 pos += siz; 79 } 80 if (hole >= 0 && data >= 0 && hole < data) { 81 siz = data - hole; 82 printf("hole #%d @ %ld, size=%jd\n", 83 n, (intmax_t)hole, siz); 84 n++; 85 pos += siz; 86 } 87 if (hole >= 0 && data == -1) { 88 siz = st.st_size - hole; 89 printf("hole #%d @ %ld, size=%jd\n", 90 n, (intmax_t)hole, siz); 91 n++; 92 pos += siz; 93 } 94 } 95 if (hole == st.st_size) { 96 /* EOF */ 97 printf("hole #%d @ %ld, size=%jd\n", 98 n, (intmax_t)hole, 0L); 99 } 100 close(fd); 101 } 102