Must use twice of "Ctrl + c" to terminate a process in the terminal emulator of Emacs.

[Hongyi Zhao]

$ emacs

Then in Emacs, do the following testing:

M-x term RET
$ sudo tcpdump -i any port 8080 -w - |pv >/dev/null

I find, if I want to terminate the above spawned process, twice of
"Ctrl + c" must be used to do the job.

Any hints for this phenomenon?

Regards
-- 
Assoc. Prof. Hongyi Zhao <hongyi.zhao@gmail.com>
Theory and Simulation of Materials
Hebei Vocational University of Technology and Engineering
NO. 552 North Gangtie Road, Xingtai, China