Introduction

The libsquashfs library attempts to encapsulate the actual core of the SquashFS reading and writing logic of the squashfs-tools-ng package, while trying to offer a generic API that should cover a broad variety of applications that might want to make use SquashFS.

All disk I/O is abstracted away through the sqfs_file_t interface. A reference implementation that uses native file I/O can be instatiated using sqfs_open_file. Providing a custom implementation allows reading or writing SquashFS images to something other than regular files, embedding SquashFS in a custom container format or applying custom transformations on the raw byte level.

If want to get started with reading SquashFS images, a good starting point would be the sqfs_data_reader_t and sqfs_dir_reader_t that provide an interface for browsing a SquashFS directory tree and reading data contained within.

A few helper structures are need for that tough, specifically the SquashFS super block (see sqfs_super_t) that can be read from a sqfs_file_t using sqfs_super_read.

A decompressor (see sqfs_compressor_t) is also needed, which can be created using sqfs_compressor_config_init and sqfs_compressor_create.