When trying to exploit an application it’s useful to send the input via gdb to immediately check how the input is being processed. But once the gdb is open it’s sometimes not clear how to pass binary input to applications reading from stdin, e.g. using read. An easy way is to start the debugging session with gdb ./binary and using

run < <(printf "\xAA\xAA\xAA")

from the gdb session to send arbitrary bytes.