1UNSQUASHFS(1) User Commands UNSQUASHFS(1)
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6 unsquashfs - tool to uncompress, extract and list squashfs filesystems
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9 unsquashfs [OPTIONS] FILESYSTEM [files to extract or exclude (with -ex‐
10 cludes) or cat (with -cat )]
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13 Squashfs is a highly compressed read-only filesystem for Linux. It
14 uses either gzip/xz/lzo/lz4/zstd compression to compress both files,
15 inodes and directories. Inodes in the system are very small and all
16 blocks are packed to minimise data overhead. Block sizes greater than
17 4K are supported up to a maximum of 1Mbytes (default block size 128K).
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19 Squashfs is intended for general read-only filesystem use, for archival
20 use (i.e. in cases where a .tar.gz file may be used), and in con‐
21 strained block device/memory systems (e.g. embedded systems) where low
22 overhead is needed.
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25 -v, -version
26 print version, licence and copyright information.
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28 -cat cat the files on the command line to stdout.
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30 -d PATHNAME, -dest PATHNAME
31 extract to PATHNAME, default "squashfs-root".
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33 -max LEVELS, -max-depth LEVELS
34 descend at most LEVELS of directories when extracting or list‐
35 ing.
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37 -excludes
38 treat files on command line as exclude files.
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40 -ex, -exclude-list
41 list of files to be excluded, terminated with ; e.g. file1 file2
42 ;.
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44 -follow, -follow-symlinks
45 follow symlinks in extract files, and add all files/symlinks
46 needed to resolve extract file. Implies -no-wildcards.
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48 -missing, -missing-symlinks
49 Unsquashfs will abort if any symlink can't be resolved in -fol‐
50 low-symlinks.
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52 -q, -quiet
53 no verbose output.
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55 -n, -no-progress
56 don't display the progress bar.
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58 -no, -no-xattrs
59 don't extract xattrs in file system.
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61 -x, -xattrs
62 extract xattrs in file system (default).
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64 -u, -user-xattrs
65 only extract user xattrs in file system. Enables extracting xat‐
66 trs.
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68 -p NUMBER, -processors NUMBER
69 use NUMBER processors. By default will use the number of pro‐
70 cessors available.
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72 -i, -info
73 print files as they are extracted.
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75 -li, -linfo
76 print files as they are extracted with file attributes (like ls
77 -l output).
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79 -l, -ls
80 list filesystem, but don't extract files.
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82 -ll, -lls
83 list filesystem with file attributes (like ls -l output), but
84 don't extract files.
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86 -lln, -llnumeric
87 same as -lls but with numeric uids and gids.
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89 -lc list filesystem concisely, displaying only files and empty di‐
90 rectories. Don't extract files.
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92 -llc list filesystem concisely with file attributes, displaying only
93 files and empty directories. Don't extract files.
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95 -o BYTES, -offset BYTES
96 skip BYTES at start of FILESYSTEM. Optionally a suffix of K, M
97 or G can be given to specify Kbytes, Mbytes or Gbytes respec‐
98 tively (default 0 bytes).
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100 -f, -force
101 if file already exists then overwrite.
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103 -ig, -ignore-errors
104 treat errors writing files to output as non-fatal.
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106 -st, -strict-errors
107 treat all errors as fatal.
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109 -no-exit, -no-exit-code
110 don't set exit code (to nonzero) on non-fatal errors.
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112 -s, -stat
113 display filesystem superblock information.
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115 -UTC use UTC rather than local time zone when displaying time.
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117 -mkfs-time
118 display filesystem superblock time, which is an unsigned 32-bit
119 int representing the time in seconds since the epoch
120 (1970-01-01).
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122 -fstime
123 synonym for -mkfs-time.
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125 -extract-file FILE
126 list of directories or files to extract. One per line.
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128 -exclude-file FILE
129 list of directories or files to exclude. One per line.
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131 -pf FILE
132 output a pseudo file equivalent of the input Squashfs filesys‐
133 tem.
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135 -pseudo-file FILE
136 alternative name for -pf.
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138 -e, -ef EXTRACT FILE
139 synonym for -extract-file.
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141 -exc, -excf EXCLUDE FILE
142 synonym for -exclude-file.
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144 -da SIZE, -data-queue SIZE
145 set data queue to SIZE Mbytes. Default 256 Mbytes.
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147 -fr SIZE, -frag-queue SIZE
148 set fragment queue to SIZE Mbytes. Default 256 Mbytes.
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150 -no-wild, -no-wildcards
151 do not use wildcard matching in extract names.
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153 -r, -regex
154 treat extract names as POSIX regular expressions rather than use
155 the default shell wildcard expansion (globbing).
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157 -L synonym for -follow-symlinks.
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159 -h, -help
160 output this options text to stdout.
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163 gzip, lzo, lz4, xz, zstd, lzma
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166 0 The filesystem listed or extracted OK.
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168 1 FATAL errors occurred, e.g. filesystem corruption, I/O errors.
169 Unsquashfs did not continue and aborted.
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171 2 Non-fatal errors occurred, e.g. no support for XATTRs, Symbolic
172 links in output filesystem or couldn't write permissions to out‐
173 put filesystem. Unsquashfs continued and did not abort.
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175 See -ignore-errors, -strict-errors and -no-exit-code options for how
176 they affect the exit status.
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179 unsquashfs IMAGE.SQFS
180 Extract IMAGE.SQFS to "squashfs-root" in the current working di‐
181 rectory.
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183 unsquashfs -d output IMAGE.SQFS
184 Extract IMAGE.SQFS to "output" in the current working directory.
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186 unsquashfs -d . IMAGE.SQFS
187 Extract IMAGE.SQFS to current working directory.
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189 unsquashfs -linfo IMAGE.SQFS
190 Output a listing of IMAGE.SQFS with file attributes to stdout,
191 while extracting the filesystem to "squashfs-root".
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193 unsquashfs -lls IMAGE.SQFS
194 Output a listing of IMAGE.SQFS with file attributes to stdout,
195 but do not extract the filesystem.
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197 unsquashfs IMAGE.SQFS fs/squashfs
198 Extract only the "fs/squashfs" directory.
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200 unsquashfs IMAGE.SQFS "[Tt]est/example*"
201 Extract all files beginning with "example" inside top level di‐
202 rectories called "Test" or "test".
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204 unsquashfs -excludes IMAGE.SQFS "test/*data*.gz"
205 This will extract everything except for files that match
206 *data*.gz in the test directory. The -excludes option tells Un‐
207 squashfs to exclude the files on the command line rather than
208 extract them.
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210 unsquashfs -ex "test/*data*.gz" ; IMAGE.SQFS test
211 This uses both extract and exclude options, to tell Unsquashfs
212 to only extract the "test" directory, and to exclude any files
213 within it that match *data*.gz.
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215 unsquashfs -dest output -max-depth 2 IMAGE.SQFS
216 Extract only the top two levels of IMAGE.SQFS to "output" direc‐
217 tory.
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219 unsquashfs -max-depth 2 IMAGE.SQFS "test/*.gz"
220 Only extract the gzipped files in the test directory.
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222 unsquashfs -llc -max-depth 2 IMAGE.SQFS "test/*.gz"
223 Output a listing of the gzipped files in the test directory to
224 stdout, but do not extract them.
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226 Note: when passing wildcarded names to Unsquashfs, they should be
227 quoted (as in the above examples), to ensure that they are not pro‐
228 cessed by the shell.
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231 Written by Phillip Lougher <phillip@squashfs.org.uk>
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234 Copyright © 2022 Phillip Lougher <phillip@squashfs.org.uk>
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236 This program is free software; you can redistribute it and/or modify it
237 under the terms of the GNU General Public License as published by the
238 Free Software Foundation; either version 2, or (at your option) any
239 later version.
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241 This program is distributed in the hope that it will be useful, but
242 WITHOUT ANY WARRANTY; without even the implied warranty of MER‐
243 CHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
244 Public License for more details.
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247 mksquashfs(1), sqfstar(1), sqfscat(1)
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249 The README for the Squash-tools 4.5.1 release, describing the new fea‐
250 tures can be read here
251 https://github.com/plougher/squashfs-tools/blob/master/README-4.5.1
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253 The Squashfs-tools USAGE guide can be read here
254 https://github.com/plougher/squashfs-tools/blob/master/USAGE
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258unsquashfs version 4.5.1 July 2022 UNSQUASHFS(1)