Maybe you ever wanted to do something like
python -c "print '\x41'*36" | binary
from inside GDB ?
Here are some solutions:
r < <(python -c "print '\x41'*36" | binary)
r <<< $(python -c "print '\x41'*36")
And, as a bonus for the < <() trick:
19:24 <%noname> diff <(cmd1) <(cmd2)
19:24 <%noname> it diffs outputs of cmd1 and cmd2