[hk1337]

I haven’t tested this exact scenario but I like doing something like this when needed

    mkdir -p path/to/{one,two,three}/done

To create:

* path/to/one/done

* path/to/two/done

* path/to/three/done

[eloisius]

Particularly helpful for quickly appending something to a file name

    mv something{,.old}

[tyingq]

Shell alternation globs do ranges too, so be careful :)

  echo -e {A..Z}{a..z}{0..9}/{A..Z}{a..z}{0..9}"\n"|wc -l
  45697601

Runs for a bit too.