Binding the result of a system command to a variable in Haskell

Question

How does one run a system command in Haskell and bind it\'s result (i.e., standard output) to a variable? In pseudo-haskell I\'m looking for something like the

Answer 1

Expanding on jamshidh's answer, if instead of getting stdout and stderr as String you want to get them as ByteString or Text, you can use the process-extras package.

You can also use my process-streaming package:

$ import System.Process.Streaming
$ execute (piped (shell "echo foo")) (liftA3 (,,) (foldOut intoLazyBytes)    
                                                  (foldErr intoLazyBytes)
                                                  exitCode)
("foo\n","",ExitSuccess)

Also for Text:

$ import System.Process.Streaming.Text
$ execute (piped (shell "echo foo")) (liftA3 (,,) (foldOut (transduce1 utf8x intoLazyText)) 
                                                  (foldErr (transduce1 utf8x intoLazyText)) 
                                                  exitCode)
("foo\n","",ExitSuccess)