squashfs is an open and free compressed read-only filesystem. It is used in embedded devices, live-CDs, or in packaging. The original implementation resides in the linux kernel, but there are also userspace implementations.
This project provides a userspace implementation of the squashfs filesystem containing a set of command line tools and a C library.
- libc: Any POSIX compliant libc should work. Open a bug if it doesn't.
- zlib optional: For gzip compression support.
- liblz4 optional: For lz4 compression support.
- liblzma optional: For lzma compression support.
- libzstd optional: For zstd compression support.
- fuse3 optional: For mounting squashfs archives.
- fuse2 optional: For mounting squashfs archives on systems that don't support fuse3. e.g. OpenBSD.
- libcurl optional: For transparently reading squashfs archives from the internet without downloading them first.
Note that to do anything useful with libsqsh, you need to have at least one of the compression libraries enabled.
meson setup build
cd build
meson compile
meson installThis project provides a set of command line tools to interact with squashfs archives.
sqsh-cat: Prints the content of one or multiple files to stdout.sqsh-ls: Lists the content of a directory.sqsh-stat: Prints the metadata of a file, directory, or the whole archive.sqsh-unpack: Extracts a squashfs archive to a directory.sqsh-xattr: Prints the extended attributes of a file or directory.sqshfs: Mounts a squashfs archive to a directory. There are two versions of this tool, one for fuse3 and one for fuse2.
libsqsh is a purely 2-Clause BSD Licensed implementation of the squashfs filesystem in C11. It covers the complete squashfs feature set, while still having minimal memory footprint.
Note that libsqsh only supports reading squashfs archives. If you want to create squashfs archives, you can either use squashfs-tools, which provides a command line interface, or squashfs-tools-ng, which provides both a command-line interface and a C library interface.
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Complete feature set: libsqsh supports all features of the squashfs file system.
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Modern C11 implementation: Written in modern C11, libsqsh is designed for efficiency and compatibility with C++, C, and other languages.
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High-Level API: The high-level API provides easy-to-use functions to access the contents of a to the contents of a squashfs archive. It is designed to be easy to use and fast to develop with.
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Low-Level API: The low-level API provides zero-copy interfaces to the squashfs archive. It is designed to be both memory and CPU efficient.
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Pure 2-Clause-BSD License: libsqsh is licensed under the 2-Clause BSD license. This allows you to use libsqsh in any project, even commercial ones.
This is a simple example that a) prints the content of a file and b) lists the content of a directory.
struct SqshArchive *archive =
sqsh_archive_open("/path/to/archive.squashfs", NULL, NULL);
uint8_t *contents = sqsh_easy_file_content(archive, "/path/to/file", NULL);
assert(contents != NULL);
const size_t size = sqsh_easy_file_size(archive, "/path/to/file", NULL);
fwrite(contents, 1, size, stdout);
free(contents);
char **files = sqsh_easy_directory_list(archive, "/path/to/dir", NULL);
assert(files != NULL);
for (int i = 0; files[i] != NULL; i++) {
puts(files[i]);
}
free(files);
sqsh_archive_close(archive);Find further examples in the examples directory.
The sqsh-tools team works hard to keep the API stable. As a result,
some functions are marked as deprecated but remain available for the
current major version. The replacements for these deprecated functions
typically have the same name with a ...2 suffix.
In the next major (at the time of writing v2.0.0) version, the ...2
functions will be renamed to their original names, and the deprecated
functions will be removed.
LZO2 is a fast compression algorithm. Unfortunately the current implementation is GPL licensed and therefore not included in this library. If you want to use LZO2 there's and independent glue library called libsqsh-lzo.
- https://dr-emann.github.io/squashfs/squashfs.html - A detailed description of the squashfs file format.
- https://github.com/plougher/squashfs-tools/ - The original squashfs-tools implementation.
- https://github.com/AgentD/squashfs-tools-ng/ - A rewrite of the squashfs-tools implementation with library support. In contrast to libsqsh, this library is able to write squashfs archives.
- https://github.com/vasi/squashfuse - A C implementation of the squashfs filesystem.
