Write byte at address (hexedit/modify binary from the command line)

Question

Is there any straightforward way to modify a binary from the commandline? Let\'s say I know that my binary contains 1234abcd and i want to change it to 12FFabcd or FFFFabcd

Answer 1

xxd tool, which comes with vim (and thus is quite likely to be available) allows to hex dump a binary file and construct a new binary file from a modified hex dump.