App - System

Hello everyone,

I try to exploit challenge ELF32 - Stack buffer overflow basic 3, but without any success.
Perhaps I found the vulnerability but I am not sure, I think that you can enter a arbitrary character, e.g. an ’A’,
64 times, to fill the buffer and because the counter increase after every copy of an character you can then overwrite
’check’ with 0xbffffabc, but splitten in every character (so first ’\xbc’, then ’\xfa’ and next), please correct me if I am wrong.
My problem is that I can’t put every character (e.g. ’\xbc’ ) in the terminal, by hand.
How I could do this?