UNIX for Dummies Questions & Answers

Hi

I hope this is the right section to post.
My question is about copyrighted code.

If I read some copyrighted source code to learn something new and then I would like to reuse one idea I liked what is the boundary to avoid rights problems?

I mean, for example, is there the chance to reuse the idea or not at all? , or (just for example) Can I use up to 3 equals code lines? or there are some different criteria?

thanks in advance

It is not really a question of copyright per se. You can easily overcome that hurdle by including the other persons copyright in your code.

The real question is the license attached to the source code.

Hi thx for reply,

Yea actually I know that but this means that also your code,
if it include (even only few lines of code or simply the same modus operandi), must be released with the same license and not under the GPL or another one, right?

Depends on the license, BSD licensing allows you include the code in any product, whereas GPL doesn't but once you reimplement the concept without pasting the code you are not in violation of copyright, though you may hit the patent issue in some jurisdictions.

ok thx

The GPL prohibits you from selling things derived directly from source using that license, it's no barrier to just using them. An important distinction that's occasionally forgotten.

Also, code using the LGPL may be used as a dynamically-linked library without license problems -- as long as people who purchase the product can freely see the code for the library, and update the library as they please, it's good. The LGPL for this reason used to be known as the "library GPL".

I think the use of the word "selling" could unintentionally mislead those not familiar with the GPL. For their benefit, I'd like to make it clear that whether one is compensated or not is irrelevant. You cannot distribute binaries based on modified GPL source without also making available the source modifications.

Regards,
Alister