od - Output file dump
od [ -a ] file…
Od displays the contents of a file in hexadecimal format, useful for inspecting the structure of binary files. The output produced appears as follows:
0000- 61946301 76DEADBE ...EFFEEDAF 0080- D21CA1FA 1FA20EDF ...D4C00BFC
By default, only hex data is shown in a tight format that displays 32 bytes-worth of data per line.
The -a option generates a looser format (16-bytes worth per line) along with an ASCII display next to each line.
Od is traditionally “octal dump”, but normal people avoid octal.
cat(C), inspect(C), tail(C)