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Comment by dorfsmay | Hacker News Reader

Any reason you don't use one of the existing scriptable scheme like guile's?

Wanted to put my article-gleaned understanding of lisp to the test + get at the essence of what shebang-style unix scripting was about.

Here is a reimplementation of "cat" in it:

    #!/usr/bin/env imp

    (def copy-out (proc (x)
      (let f (if (file? x) x (open x))
           bytes (read default-chunk f)
           (if bytes
               (seq (write bytes stdout)
                    (recur f))
               (close f)))))

    (if (nil? script-args)
        (copy-out stdin)
        (each copy-out script-args))

Running external programs is a bit more verbose than normal shell, but there is some optional reader-macro sugar on top of fork+exec, e.g. the effect of the following is that /usr/bin/say gets run with those non-string args converted to strings and a voice comes out of my speaker.

    !(say hello there)
    => ((status : 0) (pid : 2945) (in : [File]) (out : [File]) (err : [File]))

> Wanted to put my article-gleaned understanding of lisp to the test

fair enough!

> get at the essence of what shebang-style unix scripting was about

FWIW, although convoluted, you can do that with guile, with:

    #!/usr/bin/guile \
    -e main -s

Or simpler with chicken:

  #!/usr/bin/csi -s

IMHO the nicest Scheme for UNIX scripting is scsh. Its APIs are really well thought out and represent a lot of design work that hasn't ever been replicated by another Scheme (at least that I've seen).

Some good examples of scsh scripting (some by the author, Olin Shivers) can be found at

http://scsh.net/resources/scripts.html

The manual is also very good:

http://scsh.net/docu/html/man.html

> The manual is also very good

The acknowledgements section made my morning, thanks.

Do you know what is the status of scsh? It's an old project, seemingly unmaintained. Is it considered feature complete? Are there any active users of scsh? What about bugs?

Last time I checked a package for scsh for Fedora was somehow broken and/or conflicting with Chicken and I went with the latter. In general I like the idea and APIs of scsh, I'm just afraid that there will be no one to ask for help if I hit some problems. With Chicken or Racket the communities are active and it's easy to find support. How does this look in case of scsh?

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