InString[
n
] is a global object that is assigned to be the text of the n
input line.
InString[
n
] gives the string that Mathematica read for the n
input line. The string includes all intermediate newlines in the input, but not the newline at the end.
The value of InString[
n
] is assigned after the input is verified to be syntactically correct, and after any function given as the value of $PreRead has been applied.
InString[
] gives the text of the last input line.
InString[-k] gives the text of the input k lines back.
input line. 
input line. The string includes all intermediate newlines in the input, but not the newline at the end. 
