Oh is a Unix shell written in Go. It is similar in spirit but different in detail from other Unix shells.

Oh was motivated by the belief that many of the flaws in current Unix shells are not inherent but rather historical. Design choices that are clearly unfortunate in retrospect have been carried forward in the name of backward compatibility. As a re-imagining of the Unix shell, oh revisits these design choices while adding support for concurrent, functional and object-based programming.

Oh extends the shell's programming language features without sacrificing the shell's interactive features. The following commands behave as expected:

date
cat /usr/share/dict/words
who >user.names
who >>user.names
wc <file
echo [a-f]*.c
who | wc
who; date
cc *.c &
mkdir junk && cd junk
cd ..
rm -r junk || echo "rm failed!"

Oh has objects but no classes. Objects can be created from scratch using the 'object' command. Private members are defined using the 'define' command and public members are defined using the 'public' command:

define point: object {
    define x: integer 0
    define y: integer 0

    public move: method self (a b) as {
        set self::x: add self::x a
        set self::y: add self::y b
    }

    public show: method self () as {
        echo self::x self::y
    }
}

Objects can also be created by cloning an existing object:

define o: point::clone

Modules are objects. The command below creates an object called 'm'. Public, top-level definitions in 'file' can be accessed using the object 'm'.

define m: import file

Pipes are objects. Oh exposes pipes, which are implicit in other shells, as first-class values. Pipes can be created with the 'pipe' command:

define p: pipe

Oh incorporates many features, including first-class functions, from the Scheme dialect of Lisp. Like Lisp, oh uses the same syntax for code and data. When data is sent across a pipe it is converted to text so that it can be sent to (or even through) external Unix programs.

To compile and run oh you will need to install the C libraries ncurses and libtecla. On Ubuntu 12.10 do:

sudo apt-get install libncurses5-dev
sudo apt-get install libtecla1-dev

Then go get oh:

go get github.com/michaelmacinnis/oh

Oh is released under an MIT-style license.

Thanks to André Cormier for suggesting the name.