[821] | 1 | /*
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| 2 | * getsize.c --- get the size of a partition.
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| 3 | *
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| 4 | * Copyright (C) 1995, 1995 Theodore Ts'o.
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| 5 | *
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| 6 | * %Begin-Header%
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| 7 | * This file may be redistributed under the terms of the
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| 8 | * GNU Lesser General Public License.
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| 9 | * %End-Header%
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| 10 | */
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| 11 |
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| 12 | /* include this before sys/queues.h! */
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| 13 | #include "blkidP.h"
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| 14 |
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| 15 | #include <stdio.h>
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| 16 | #if HAVE_UNISTD_H
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| 17 | #include <unistd.h>
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| 18 | #endif
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| 19 | #if HAVE_ERRNO_H
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| 20 | #include <errno.h>
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| 21 | #endif
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| 22 | #include <fcntl.h>
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| 23 | #ifdef HAVE_SYS_IOCTL_H
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| 24 | #include <sys/ioctl.h>
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| 25 | #endif
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| 26 | #ifdef HAVE_LINUX_FD_H
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| 27 | #include <linux/fd.h>
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| 28 | #endif
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| 29 | #ifdef HAVE_SYS_DISKLABEL_H
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| 30 | #include <sys/disklabel.h>
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| 31 | #include <sys/stat.h>
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| 32 | #endif
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| 33 | #ifdef HAVE_SYS_DISK_H
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| 34 | #ifdef HAVE_SYS_QUEUE_H
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| 35 | #include <sys/queue.h> /* for LIST_HEAD */
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| 36 | #endif
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| 37 | #include <sys/disk.h>
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| 38 | #endif
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| 39 | #ifdef __linux__
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| 40 | #include <sys/utsname.h>
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| 41 | #endif
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| 42 |
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| 43 | #if defined(__linux__) && defined(_IO) && !defined(BLKGETSIZE)
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| 44 | #define BLKGETSIZE _IO(0x12,96) /* return device size */
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| 45 | #endif
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| 46 |
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| 47 | #if defined(__linux__) && defined(_IOR) && !defined(BLKGETSIZE64)
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| 48 | #define BLKGETSIZE64 _IOR(0x12,114,size_t) /* return device size in bytes (u64 *arg) */
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| 49 | #endif
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| 50 |
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| 51 | #ifdef APPLE_DARWIN
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| 52 | #define BLKGETSIZE DKIOCGETBLOCKCOUNT32
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| 53 | #endif /* APPLE_DARWIN */
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| 54 |
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| 55 | static int valid_offset(int fd, blkid_loff_t offset)
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| 56 | {
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| 57 | char ch;
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| 58 |
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| 59 | if (blkid_llseek(fd, offset, 0) < 0)
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| 60 | return 0;
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| 61 | if (read(fd, &ch, 1) < 1)
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| 62 | return 0;
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| 63 | return 1;
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| 64 | }
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| 65 |
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| 66 | /*
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| 67 | * Returns the number of blocks in a partition
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| 68 | */
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| 69 | blkid_loff_t blkid_get_dev_size(int fd)
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| 70 | {
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| 71 | int valid_blkgetsize64 = 1;
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| 72 | #ifdef __linux__
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| 73 | struct utsname ut;
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| 74 | #endif
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| 75 | unsigned long long size64;
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| 76 | unsigned long size;
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| 77 | blkid_loff_t high, low;
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| 78 | #ifdef FDGETPRM
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| 79 | struct floppy_struct this_floppy;
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| 80 | #endif
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| 81 | #ifdef HAVE_SYS_DISKLABEL_H
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| 82 | int part = -1;
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| 83 | struct disklabel lab;
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| 84 | struct partition *pp;
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| 85 | char ch;
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| 86 | struct stat st;
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| 87 | #endif /* HAVE_SYS_DISKLABEL_H */
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| 88 |
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| 89 | #ifdef DKIOCGETBLOCKCOUNT /* For Apple Darwin */
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| 90 | if (ioctl(fd, DKIOCGETBLOCKCOUNT, &size64) >= 0) {
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| 91 | if ((sizeof(blkid_loff_t) < sizeof(unsigned long long))
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| 92 | && (size64 << 9 > 0xFFFFFFFF))
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| 93 | return 0; /* EFBIG */
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| 94 | return (blkid_loff_t) size64 << 9;
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| 95 | }
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| 96 | #endif
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| 97 |
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| 98 | #ifdef BLKGETSIZE64
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| 99 | #ifdef __linux__
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| 100 | if ((uname(&ut) == 0) &&
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| 101 | ((ut.release[0] == '2') && (ut.release[1] == '.') &&
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| 102 | (ut.release[2] < '6') && (ut.release[3] == '.')))
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| 103 | valid_blkgetsize64 = 0;
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| 104 | #endif
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| 105 | if (valid_blkgetsize64 &&
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| 106 | ioctl(fd, BLKGETSIZE64, &size64) >= 0) {
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| 107 | if ((sizeof(blkid_loff_t) < sizeof(unsigned long long))
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| 108 | && ((size64) > 0xFFFFFFFF))
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| 109 | return 0; /* EFBIG */
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| 110 | return size64;
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| 111 | }
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| 112 | #endif
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| 113 |
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| 114 | #ifdef BLKGETSIZE
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| 115 | if (ioctl(fd, BLKGETSIZE, &size) >= 0)
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| 116 | return (blkid_loff_t)size << 9;
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| 117 | #endif
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| 118 |
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| 119 | #ifdef FDGETPRM
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| 120 | if (ioctl(fd, FDGETPRM, &this_floppy) >= 0)
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| 121 | return (blkid_loff_t)this_floppy.size << 9;
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| 122 | #endif
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| 123 | #ifdef HAVE_SYS_DISKLABEL_H
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| 124 | #if 0
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| 125 | /*
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| 126 | * This should work in theory but I haven't tested it. Anyone
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| 127 | * on a BSD system want to test this for me? In the meantime,
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| 128 | * binary search mechanism should work just fine.
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| 129 | */
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| 130 | if ((fstat(fd, &st) >= 0) && S_ISBLK(st.st_mode))
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| 131 | part = st.st_rdev & 7;
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| 132 | if (part >= 0 && (ioctl(fd, DIOCGDINFO, (char *)&lab) >= 0)) {
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| 133 | pp = &lab.d_partitions[part];
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| 134 | if (pp->p_size)
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| 135 | return pp->p_size << 9;
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| 136 | }
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| 137 | #endif
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| 138 | #endif /* HAVE_SYS_DISKLABEL_H */
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| 139 |
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| 140 | /*
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| 141 | * OK, we couldn't figure it out by using a specialized ioctl,
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| 142 | * which is generally the best way. So do binary search to
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| 143 | * find the size of the partition.
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| 144 | */
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| 145 | low = 0;
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| 146 | for (high = 1024; valid_offset(fd, high); high *= 2)
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| 147 | low = high;
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| 148 | while (low < high - 1)
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| 149 | {
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| 150 | const blkid_loff_t mid = (low + high) / 2;
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| 151 |
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| 152 | if (valid_offset(fd, mid))
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| 153 | low = mid;
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| 154 | else
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| 155 | high = mid;
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| 156 | }
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| 157 | return low + 1;
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| 158 | }
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| 159 |
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| 160 | #ifdef TEST_PROGRAM
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| 161 | int main(int argc, char **argv)
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| 162 | {
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| 163 | blkid_loff_t bytes;
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| 164 | int fd;
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| 165 |
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| 166 | if (argc < 2) {
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| 167 | fprintf(stderr, "Usage: %s device\n"
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| 168 | "Determine the size of a device\n", argv[0]);
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| 169 | return 1;
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| 170 | }
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| 171 |
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| 172 | if ((fd = open(argv[1], O_RDONLY)) < 0)
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| 173 | perror(argv[0]);
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| 174 |
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| 175 | bytes = blkid_get_dev_size(fd);
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| 176 | printf("Device %s has %lld 1k blocks.\n", argv[1], bytes >> 10);
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| 177 |
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| 178 | return 0;
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| 179 | }
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| 180 | #endif
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