SQFSCAT(1) User Commands SQFSCAT(1)
NAME
sqfscat - tool to cat files from a squashfs filesystem to stdout
SYNOPSIS
sqfscat [OPTIONS] FILESYSTEM [list of files to cat to stdout]
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 con-
strained block device/memory systems (e.g. embedded systems) where low
overhead is needed.
OPTIONS
-v, -version
print version, licence and copyright information.
-p NUMBER, -processors NUMBER
use NUMBER processors. By default will use the number of
processors available.
-o BYTES, -offset BYTES
skip BYTES at start of FILESYSTEM. Optionally a suffix of K, M
or G can be given to specify Kbytes, Mbytes or Gbytes respec-
tively (default 0 bytes).
-ig, -ignore-errors
treat errors writing files to stdout as non-fatal.
-st, -strict-errors
treat all errors as fatal.
-no-exit, -no-exit-code
don't set exit code (to nonzero) on non-fatal errors.
-da SIZE, -data-queue SIZE
set data queue to SIZE Mbytes. Default 256 Mbytes.
-fr SIZE, -frag-queue SIZE
set fragment queue to SIZE Mbytes. Default 256 Mbytes.
-no-wild, -no-wildcards
do not use wildcard matching in filenames.
-r, -regex
treat filenames as POSIX regular expressions rather than use the
default shell wildcard expansion (globbing).
-h, -help
output options text to stdout.
DECOMPRESSORS AVAILABLE
gzip, lzo, lz4, xz, zstd, lzma
EXIT STATUS
0 The file or files were output to stdout OK.
1 FATAL errors occurred, e.g. filesystem corruption, I/O errors.
Sqfscat did not continue and aborted.
2 Non-fatal errors occurred, e.g. not a regular file, or failed to
resolve pathname. Sqfscat continued and did not abort.
See -ignore-errors, -strict-errors and -no-exit-code options for how
they affect the exit status.
EXAMPLES
sqfscat IMAGE.SQFS hello
Output the contents of "hello" to stdout.
sqfscat IMAGE.SQFS hello world
Output the contents of "hello" and then "world" to stdout.
sqfscat IMAGE.SQFS "*.[ch]"
Output the contents of all the files in the root directory that
match the wildcard *.[ch], to stdout, e.g. hello.c, hello.h,
world.c, world.h.
Note: when passing wildcarded names to Sqfscat, they should be quoted
(as in the above examples), to ensure that they are not processed by
the shell.
AUTHOR
Written by Phillip Lougher <phillip@squashfs.org.uk>
COPYRIGHT
Copyright © 2023 Phillip Lougher <phillip@squashfs.org.uk>
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.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of MER-
CHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
Public License for more details.
SEE ALSO
mksquashfs(1), unsquashfs(1), sqfstar(1)
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
The Squashfs-tools USAGE guide can be read here
https://github.com/plougher/squashfs-tools/blob/master/USAGE-4.6
sqfscat version 4.6.1 April 2024 SQFSCAT(1)
Generated by dwww version 1.16 on Tue Dec 16 15:05:57 CET 2025.