Support `dd` functionality

[ellcs]

Error: No binding for 'dd'. Did you mean 'cd'?
dd
^-

I just assume that every unix program needs it's own binding. Where do add a binding and how do i write one?

Cheers!

[mdr]

I just assume that every unix program needs it's own binding

Yeah, the intention is that Mash should provide built-in support for most standard Unix functionality, including programs like dd, although it might end up with a different interface than the traditional command (dd actually being a good example that it has different argument convention to most programs).

Where do add a binding and how do i write one?

At the moment, for standard lib functions, they are written in Scala. There's an example binding to open in src/main/scala/com/github/mdr/mash/ns/os/OpenFunction.scala

You could also write a dd binding in Mash, as a user function. A simple one might look like:

def dd (in="/dev/stdin") (out="/dev/stdout") (blockSize=512) (count=1) = 
  !!{dd "if=$in" "of=$out" "bs=$blockSize" "count=$count"}

(And if you just want to run the dd executable, you can also do that using the "mish" subsyntax, e.g. by prepending an ! at the start: !dd if=/dev/urandom of=myrandom bs=100 count=1)