[geophile]

A UI is great if it does exactly what you want it to do. But if not, and you want to customize at all, you're stuck. While if you're working on the command line, you can script any behavior you'd like.

A command line approach is also far superior for remote operation, repetition, combining with other tools, etc., because you can script the interactions and control flow.

[bediger]

If I might rephrase geophile, above: a command line (most of them, anyway) has a grammar, complete with flow-of-control constructs like if-then-else, while loops, for-loops.

You can express more with a grammar than without one. For example, you can express palindrome strings with a grammar, you can't with regular expressions.

We can tail off into philosophy by talking about "generative grammars" allowing you to create new ideas, and this may be what geophile says about "[G]UI is great if it does exactly what you want it to do. But if not, and you want to customize at all, you're stuck." I agree with this sentiment.

[mwdev]

I'll give you that the flexibility of the command line can be a help if you're really trying to do something outside the lines, but I'll disagree with the second. If we were in 1998 I'd agree, but with the remote desktop tools we have today there really isn't much of an advantage unless you are bandwidth limited.