I love pv. It's great because it's pretty much a drop-in for "cat" that gives you fancy progress bars. But for copy I tend to use "rsync -aP". It has progress but not a bar and just feels more like a replacement for cp to me.

I like pv and find myself using it when bziping large files (where the blocker is bzip). It must have a negative impact on the speed of a copy.

*Hmmm, I can't back up my own predictions:

    cp huge blah           0.11s user 7.94s system 6% cpu 2:12.54 total
    pv < huge > something  0.12s user 8.10s system 7% cpu 1:54.86 total

For those of you interested in making it a permanent replacement for cp, you can use this Python script:

    #!/usr/bin/env python
    from sys import argv
    from subprocess import Popen
    copy_from = open(argv[-2],'r')
    copy_to = open(argv[-1],'w')
    Popen("pv", stdin=copy_from, stdout=copy_to)
    copy_from.close()
    copy_to.close()

Just alias cp to it in Bash.

Alternatively, you could just write a shell function:

   cp() { pv < $1 > $2; }

(Or name the function something else if you want regular cp still available.)

Quote the variables.

Ah, good point. I'm personally used to zsh, which doesn't have that particular misfeature.

Um... in what universe would you want an interactive terminal gadget to become the default implementation of cp? Yikes.

Still, nice pointer to the pv tool, which I hadn't heard of.

Still still, the linked awk snipped is awfully clever and more fun to read.

What? I think the override is fine in an interactive environment.

My team and I use a hack which overrides cd and as well as calling builtin cd it sources a script if it exists from cwd. This means you can get the exact enviroment you need for that working copy of a project.

Mac users will be happy to learn that:

  sudo port install pv

"just works" :-) (Well, assuming you use MacPorts anyway.)