path: root/manpages/unsquashfs.1

.\" DO NOT MODIFY THIS FILE!  It was generated by help2man 1.48.5.
.TH UNSQUASHFS "1" "March 2023" "unsquashfs version 4.6.1" "User Commands"
.SH NAME
unsquashfs - tool to uncompress, extract and list squashfs filesystems
.SH SYNOPSIS
.B unsquashfs
[\fI\,OPTIONS\/\fR] \fI\,FILESYSTEM \/\fR[\fI\,files to extract or exclude (with -excludes) or cat (with -cat )\/\fR]
.SH DESCRIPTION
Squashfs is a highly compressed read-only filesystem for Linux.
It uses either gzip/xz/lzo/lz4/zstd compression to compress both files, inodes
and directories.  Inodes in the system are very small and all blocks are
packed to minimise data overhead. Block sizes greater than 4K are supported
up to a maximum of 1Mbytes (default block size 128K).

Squashfs is intended for general read-only filesystem use, for archival
use (i.e. in cases where a .tar.gz file may be used), and in constrained
block device/memory systems (e.g. embedded systems) where low overhead is
needed.
.SH OPTIONS
.SS "Filesystem extraction (filtering) options:"
.TP
\fB\-d\fR PATHNAME, \fB\-dest\fR PATHNAME
extract to PATHNAME, default "squashfs\-root". This option also sets the prefix used when listing the filesystem.
.TP
\fB\-max\fR LEVELS, \fB\-max\-depth\fR LEVELS
descend at most LEVELS of directories when extracting.
.TP
\fB\-excludes\fR
treat files on command line as exclude files.
.TP
\fB\-ex\fR, \fB\-exclude\-list\fR
list of files to be excluded, terminated with ; e.g. file1 file2 ;.
.TP
\fB\-extract\-file\fR FILE
list of directories or files to extract. One per line.
.TP
\fB\-exclude\-file\fR FILE
list of directories or files to exclude. One per line.
.TP
\fB\-match\fR
abort if any extract file does not match on anything, and can not be resolved.  Implies \fB\-missing\-symlinks\fR and \fB\-no\-wildcards\fR.
.TP
\fB\-follow\fR, \fB\-follow\-symlinks\fR
follow symlinks in extract files, and add all files/symlinks needed to resolve extract file. Implies \fB\-no\-wildcards\fR.
.TP
\fB\-missing\fR, \fB\-missing\-symlinks\fR
Unsquashfs will abort if any symlink can't be resolved in \fB\-follow\-symlinks\fR.
.TP
\fB\-no\-wild\fR, \fB\-no\-wildcards\fR
do not use wildcard matching in extract and exclude names.
.TP
\fB\-r\fR, \fB\-regex\fR
treat extract names as POSIX regular expressions rather than use the default shell wildcard expansion (globbing).
.TP
\fB\-all\fR TIME, \fB\-all\-time\fR TIME
set all file timestamps to TIME, rather than the time stored in the filesystem inode.  TIME can be an unsigned 32\-bit int indicating seconds since the epoch (1970\-01\-01) or a string value which is passed to the "date" command to parse. Any string value which the date command recognises can be used such as "now", "last week", or "Wed Feb 15 21:02:39 GMT 2023".
.TP
\fB\-cat\fR
cat the files on the command line to stdout.
.TP
\fB\-f\fR, \fB\-force\fR
if file already exists then overwrite.
.TP
\fB\-pf\fR FILE
output a pseudo file equivalent of the input Squashfs filesystem, use \- for stdout.
.SS "Filesystem information and listing options:"
.TP
\fB\-s\fR, \fB\-stat\fR
display filesystem superblock information.
.TP
\fB\-max\fR LEVELS, \fB\-max\-depth\fR LEVELS
descend at most LEVELS of directories when listing.
.TP
\fB\-i\fR, \fB\-info\fR
print files as they are extracted.
.TP
\fB\-li\fR, \fB\-linfo\fR
print files as they are extracted with file attributes (like ls \fB\-l\fR output).
.TP
\fB\-l\fR, \fB\-ls\fR
list filesystem, but do not extract files.
.TP
\fB\-ll\fR, \fB\-lls\fR
list filesystem with file attributes (like ls \fB\-l\fR output), but do not extract files.
.TP
\fB\-lln\fR, \fB\-llnumeric\fR
same as \fB\-lls\fR but with numeric uids and gids.
.TP
\fB\-lc\fR
list filesystem concisely, displaying only files and empty directories.  Do not extract files.
.TP
\fB\-llc\fR
list filesystem concisely with file attributes, displaying only files and empty directories. Do not extract files.
.TP
\fB\-full\fR, \fB\-full\-precision\fR
use full precision when displaying times including seconds.  Use with \fB\-linfo\fR, \fB\-lls\fR, \fB\-lln\fR and \fB\-llc\fR.
.TP
\fB\-UTC\fR
use UTC rather than local time zone when displaying time.
.TP
\fB\-mkfs\-time\fR
display filesystem superblock time, which is an unsigned 32\-bit int representing the time in seconds since the epoch (1970\-01\-01).
.SS "Filesystem extended attribute (xattrs) options:"
.TP
\fB\-no\fR, \fB\-no\-xattrs\fR
do not extract xattrs in file system.
.TP
\fB\-x\fR, \fB\-xattrs\fR
extract xattrs in file system (default).
.TP
\fB\-xattrs\-exclude\fR REGEX
exclude any xattr names matching REGEX. REGEX is a POSIX regular expression, e.g. \fB\-xattrs\-exclude\fR '^user.' excludes xattrs from the user namespace.
.TP
\fB\-xattrs\-include\fR REGEX
include any xattr names matching REGEX. REGEX is a POSIX regular expression, e.g. \fB\-xattrs\-include\fR '^user.' includes xattrs from the user namespace.
.SS "Unsquashfs runtime options:"
.TP
\fB\-v\fR, \fB\-version\fR
print version, licence and copyright information.
.TP
\fB\-p\fR NUMBER, \fB\-processors\fR NUMBER
use NUMBER processors.  By default will use the number of processors available.
.TP
\fB\-q\fR, \fB\-quiet\fR
no verbose output.
.TP
\fB\-n\fR, \fB\-no\-progress\fR
do not display the progress bar.
.TP
\fB\-percentage\fR
display a percentage rather than the full progress bar.  Can be used with dialog \fB\-\-gauge\fR etc.
.TP
\fB\-ig\fR, \fB\-ignore\-errors\fR
treat errors writing files to output as non\-fatal.
.TP
\fB\-st\fR, \fB\-strict\-errors\fR
treat all errors as fatal.
.TP
\fB\-no\-exit\fR, \fB\-no\-exit\-code\fR
do not set exit code (to nonzero) on non\-fatal errors.
.TP
\fB\-da\fR SIZE, \fB\-data\-queue\fR SIZE
set data queue to SIZE Mbytes.  Default 256 Mbytes.
.TP
\fB\-fr\fR SIZE, \fB\-frag\-queue\fR SIZE
set fragment queue to SIZE Mbytes.  Default 256 Mbytes.
.SS "Miscellaneous options:"
.TP
\fB\-h\fR, \fB\-help\fR
output this options text to stdout.
.TP
\fB\-o\fR BYTES, \fB\-offset\fR BYTES
skip BYTES at start of FILESYSTEM.  Optionally a suffix of K, M or G can be given to specify Kbytes, Mbytes or Gbytes respectively (default 0 bytes).
.TP
\fB\-fstime\fR
synonym for \fB\-mkfs\-time\fR.
.TP
\fB\-e\fR, \fB\-ef\fR EXTRACT FILE
synonym for \fB\-extract\-file\fR.
.TP
\fB\-exc\fR, \fB\-excf\fR EXCLUDE FILE
synonym for \fB\-exclude\-file\fR.
.TP
\fB\-L\fR
synonym for \fB\-follow\-symlinks\fR.
.TP
\fB\-pseudo\-file\fR FILE
alternative name for \fB\-pf\fR.
.SH "DECOMPRESSORS AVAILABLE"
gzip, lzo, lz4, xz, zstd
.SH "EXIT STATUS"
.TP
0
The filesystem listed or extracted OK.
.TP
1
FATAL errors occurred, e.g. filesystem corruption, I/O errors. Unsquashfs did not continue and aborted.
.TP
2
Non\-fatal errors occurred, e.g. no support for XATTRs, Symbolic links in output filesystem or couldn't write permissions to output filesystem. Unsquashfs continued and did not abort.
.PP
See \fB\-ignore\-errors\fR, \fB\-strict\-errors\fR and \fB\-no\-exit\-code\fR options for how they affect
the exit status.
.SH EXAMPLES
.TP
unsquashfs IMAGE.SQFS
Extract IMAGE.SQFS to "squashfs-root" in the current working directory.
.TP
unsquashfs -d output IMAGE.SQFS
Extract IMAGE.SQFS to "output" in the current working directory.
.TP
unsquashfs -d . IMAGE.SQFS
Extract IMAGE.SQFS to current working directory.
.TP
unsquashfs -linfo IMAGE.SQFS
Output a listing of IMAGE.SQFS with file attributes to stdout, while extracting
the filesystem to "squashfs-root".
.TP
unsquashfs -lls IMAGE.SQFS
Output a listing of IMAGE.SQFS with file attributes to stdout, but do not
extract the filesystem.  The listing will be prefixed with "squashfs-root".
.TP
unsquashfs -d "" -lls IMAGE.SQFS
Output a listing of IMAGE.SQFS with file attributes to stdout, but do not
extract the filesystem.  The listing will not be prefixed with "squashfs-root".
.TP
unsquashfs IMAGE.SQFS fs/squashfs
Extract only the "fs/squashfs" directory.
.TP
unsquashfs IMAGE.SQFS "[Tt]est/example*"
Extract all files beginning with "example" inside top level directories
called "Test" or "test".
.TP
unsquashfs -excludes IMAGE.SQFS "test/*data*.gz"
This will extract everything except for files that match *data*.gz in the
test directory.  The -excludes option tells Unsquashfs to exclude the files
on the command line rather than extract them.
.TP
unsquashfs -excludes IMAGE.SQFS "... *.gz"
This will extract everything except for files that match *.gz anywhere
in the image.   The "..." means this is a non-anchored exclude which
matches anywhere.
.TP
unsquashfs -ex "test/*data*.gz" \; IMAGE.SQFS test
This uses both extract and exclude options, to tell Unsquashfs to only
extract the "test" directory, and to exclude any files within it that
match *data*.gz.
.TP
unsquashfs -ex "... *.gz" IMAGE.SQFS test
This uses both extract and exclude options, to tell Unsquashfs to only
extract the "test" directory, and to exclude files which match "*.gz"
anywhere within "test" directory or sub-directories.
.TP
unsquashfs -dest output -max-depth 2 IMAGE.SQFS
Extract only the top two levels of IMAGE.SQFS to "output" directory.
.TP
unsquashfs -max-depth 2 IMAGE.SQFS "test/*.gz"
Only extract the gzipped files in the test directory.
.TP
unsquashfs -llc -max-depth 2 IMAGE.SQFS "test/*.gz"
Output a listing of the gzipped files in the test directory to stdout,
but do not extract them.
.TP
unsquashfs -no-xattrs IMAGE.SQFS
Do not extract any extended attributes.  Any extended attributes in the
filesystem will be ignored.
.TP
unsquashfs -xattrs-include "^user." IMAGE.SQFS
Filter the extended attributes and only extract extended attributes in the
user namespace from the Squashfs filesystem.
.TP
unsquashfs -xattrs-exclude "^user." IMAGE.SQFS
Filter the extended attributes and do not extract any extended attributes in
the user namespace from the Squashfs filesystem.
.PP
Note: when passing wildcarded names to Unsquashfs, they should be quoted (as in
the above examples), to ensure that they are not processed by the shell.
.SH AUTHOR
Written by Phillip Lougher <phillip@squashfs.org.uk>
.SH COPYRIGHT
Copyright \(co 2023 Phillip Lougher <phillip@squashfs.org.uk>
.PP
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2,
or (at your option) any later version.
.PP
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.
.SH "SEE ALSO"
mksquashfs(1), sqfstar(1), sqfscat(1)
.PP
The README for the Squashfs\-tools 4.6.1 release, describing the new features can be
read here https://github.com/plougher/squashfs\-tools/blob/master/README\-4.6.1
.PP
The Squashfs\-tools USAGE guide can be read here
https://github.com/plougher/squashfs\-tools/blob/master/USAGE\-4.6