check_tcp send string char(28)

I need to open a tcp port, send an xml message and check the result string for a given value. I believe check_tcp should work perfect for this using the -s and -e options. However, I have to include a char(28) character at the end of the send string in order for the listening app to realize it has the complete message. Could anyone tell me how to include a non-printable control character as part of the service command? Should I be using a different plugin to accomplish the test?

Thanks,
Tony

it possibly needs some escaping…

have a look at the code of check_http whch does send some command… possibly it gives a clue… (even if thinking about i think it0’s in C and gets compiled :confused: )