HexDump

Hexdump is a computer utility that presents binary data in a human-readable form by mapping bytes to hexadecimal values and, in most implementations, displaying a corresponding ASCII representation. It is commonly used for inspecting files, debugging data formats, and analyzing network packets or memory dumps. The tool reads input from a file or standard input and writes lines that include an offset, a sequence of hexadecimal byte values, and an ASCII translation for printable characters.

Output formats vary by implementation. The canonical form, often invoked with the -C option, shows offsets in hexadecimal, hex bytes grouped in fixed-width blocks, and ASCII characters aligned to the right. Other options control how much data is shown (-n), where to start (-s), and how input is formatted (-e allows custom per-field format strings). Some versions support multiple -e expressions to format different data sizes or types. The -v option may be used to ensure all data is dumped, including repeated lines.

Hex dump tools are widely available on Unix-like systems and appear in BSD-derived utilities as well as GNU/Linux environments. They are related to but distinct from the od utility, which prints data in various radixes with user-defined formats, and from xxd, which produces a more compact hex dump suitable for patching. Modern workflows may choose between them depending on the required formatting or scripting convenience.