Streaming Component Combinators



If you have Cabal-Install installed, the following two commands should install the latest SCC package on your system:

cabal update
cabal install scc

If everything goes well, there should be executable named shsh. On Unix it gets installed in your $HOME/.cabal/bin/ directory by default.

Command-line Shell

To see the options supported by shsh, type shsh --help and you'll get:

Usage: shsh (-c <command> | -f <file> | -i | -s) 
  -c       --command      Execute a single command
  -h       --help         Show help
  -f file  --file=file    Execute commands from a script file
  -i       --interactive  Execute commands interactively
  -s       --stdin        Execute commands from the standard input

Here are a few simple command examples:

 Bash + GNU tools          shsh
 ----------------          ----
 echo "Hello, World!"      echo "Hello, World!\n"
 wc -c                     count | show | concatenate
 wc -l                     foreach line then substitute x else suppress end | count | show | concatenate
 grep "foo"                foreach line having substring "foo" then append "\n" else suppress end
 sed "s:foo:bar:"          foreach substring "foo" then substitute "bar" end
 sed "s:foo:[\\&]:"        foreach substring "foo" then prepend "[" | append "]" end
 sed "s:foo:[\\&, \\&]:"   foreach substring "foo" then id; echo ", "; id end

Using the framework from Haskell

The shell interface is basically only syntax on top of the underlying EDSL (embedded domain-specific language) in Haskell. If you require anything more than stringing together of existing components using existing combinators, you'll need to write Haskell code.