plagiarism detetction tool

I've created a plagiarism detection tool but facing some difficulties for the [login to view URL] work flow goes as follows, a file system is maintained to store the input and the [login to view URL] user is allowed to chose a file(file1) for which plagiarism is to be detected ,now by accessing the content in this file ,the google API looks for the top links and data from the first link is copied in file2 and then from both the files the stop words are removed after tokenizing the words and the contents are compared, this is syntactic analysis, also i've tried to incorporate the synonyms replaced to check for symantic plagiarism but facing some issues for the same . i am also facing issue to print the amount of plagiarised content on the console and also to write it in the file.