Code for identifying programming language in a text file [closed]

Answer 1

This one is not fast and may not satisfy your requirements, but just an idea. It should be easy to implement and should give 100% result.

You could try to compile/execute the input text with different compilers/interpreters (opensource or free) and check for errors behind the scene.

Answer 2

You have a problem of document classification. I suggest you read about naive bayes classifiers and support vector machines. In the articles there are links to libraries which implement these algorithms and many of them have C++ interfaces.

Answer 3

The Sequitur algorithm infers context-free grammars from sequences of terminal symbols. Perhaps you could use that to compare against a set of known production rules for each language.

Answer 4

I'm sorry but if you have to parse thousands of files, then your best bet is to look at the file extension. Don't over engineer a simple problem, or put burdensome requirements on a simply task.

It sounds like you have thousands of files of source code and you have no idea what programming language they were written in. What kind of programming environment do you work in? (Ruling out the possibility of an artificial homework requirement) I mean one of the basics of software engineering that I can always rely on are that c++ code files have .cpp extension, that java code files have the .java extension, that c code files have the .c extension etc... Is your company playing fast and loose with these standards? If so I would be really worried.