fview

fview is a command-line tool designed for viewing and analyzing flat files, often used in the context of firmware reverse engineering or low-level data examination. Its primary function is to interpret raw byte sequences as structured data based on a user-defined format. This allows for the dissection of binary files without relying on predefined file system structures.

The tool works by taking a file and a format description as input. The format description is typically written in a specific syntax that defines data types, offsets, and potentially repeating structures. fview then reads the file byte by byte and interprets these bytes according to the provided format. Common data types supported include integers of various sizes (e.g., 8-bit, 16-bit, 32-bit), strings, and arrays.

This capability makes fview particularly useful for understanding the internal layout of embedded system firmware images, custom data structures, or any file where the organization of data is not readily apparent through standard file utilities. By specifying the layout, users can effectively "cast" the raw bytes into a more human-readable and analyzable form, revealing fields, parameters, or other meaningful information contained within the binary data. It aids in tasks such as identifying configuration parameters, extracting specific data blobs, or understanding the memory map of a firmware image.