getline(inFile, line) doesn't exist for character arrays----that's a special overload for std::strings. The one you want for a char array looks like inFile.getline(line,length). Reference here:
http://www.cplusplus.com/reference/i...m/getline.html

I have to use character arrays instead of strings.
I must use the linear search (something that looks like this)
Shame, without these restrictions you could write the program in about 10 lines using a std::map.