only matlab

You will write a function called as "character_finder" which will find the number of existence of as specific character in a text file. The function will take two input arguments: i) "fileName" as the char vector of the filename and ii) the "character" as the specific character that will be counted. The returning argument will be called as "numberOfChar", the number of characters that are found. If the input argument "character" is not a valid char or if the file does not exist in the working directory, the function will return -1