ESL receives input from the keyboard just as if the characters were being received from a local or remote application. Thus, the following statements work with the keyboard in exactly the same way as they do with an application:
Statement  | 
Description  | 
response to line  | 
Response statement for a line of input.  | 
response to char  | 
Response statement for any character(s).  | 
make string disposition  | 
Action statement to hold, drop, or immediately handle character input.  | 
input  | 
Built-in function containing the received characters.  | 
Matching Special Characters from the Keyboard
In a match clause in a response to char or response to line response statement, ESL can match special characters and key combinations.