UNIX pipes are only a tiny bit like OS X Services from a user's perspective. They are nothing alike from a program's perspective.
As others have said, UNIX pipes simply connect one program's standard output to another program's standard input. That's all. It uses the exact same mechanism that would otherwise show information to you and accept input from you.
OS X Services are a completely different, proprietary thing. It works via the 'Pasteboard' which is rather like a secondary clipboard. Apple created a specific interface which must be recognized by a program in order to supply OS X Services with data. This interface is wholly unrelated to the rest of the program's interfaces.
OS X Services are much more akin to something that you would build on Windows using COM, like a Windows Explorer Shell Extension.
If you wanted to recreate OS X Services on Linux, you would have to define some sort of new interface for exchanging data between applications, then convince developers around the world to add the new API into their programs.
FYI - My question changed from the similarity of pipes and services to just thinking about how something like services could be implemented on Linux. I did take a look at GnuStep Services, but is it the way someone would have done, if starting from a clean slate ?
Powershell has a "pipeline" as well which works at object level. Again, it may not be the same thing as pipes or services implementation-wise, but it is conceptually relevant.
http://blogs.msdn.com/b/oldnewthing/archive/2009/01/20/93411...
UNIX pipes are only a tiny bit like OS X Services from a user's perspective. They are nothing alike from a program's perspective.
As others have said, UNIX pipes simply connect one program's standard output to another program's standard input. That's all. It uses the exact same mechanism that would otherwise show information to you and accept input from you.
OS X Services are a completely different, proprietary thing. It works via the 'Pasteboard' which is rather like a secondary clipboard. Apple created a specific interface which must be recognized by a program in order to supply OS X Services with data. This interface is wholly unrelated to the rest of the program's interfaces.
OS X Services are much more akin to something that you would build on Windows using COM, like a Windows Explorer Shell Extension.
If you wanted to recreate OS X Services on Linux, you would have to define some sort of new interface for exchanging data between applications, then convince developers around the world to add the new API into their programs.