comint-input-filter-functions

comint-input-filter-functions is a variable defined in `comint.el'.
Its value is

nil

• This variable's value is permanent if it is given a local binding.
• This variable may be risky if used as a file-local variable.

Documentation:
Abnormal hook run before input is sent to the process.
These functions get one argument, a string containing the text to send.