In Emacs using ido-mode allows me to open a file from the minibuffer with C-x C-f. This method opens only one file at a time. How do I open all the files in a directory or specify more than one file to open?
You can just provide *
as the file name and press Enter; you'll be asked for a confirmation and if you press Enter a second time, all files in the directory will be opened.
Note that "opening all files in a directory" involves opening dired buffers for all of its subdirectories.
When not using ido-mode -- at the basic Emacs find-file prompt -- you can use the same *
to open all files in a directory. When you do use ido-mode to find files, you can always press C-f to drop back to the usual Emacs find-file prompt. (You can use ido to speed up getting to some directory you're interested in first and drop to the basic find-file in there.) That's one way of creating a new file with ido (the other being the C-j binding); also, it gives you another way of using the above mentioned *
trick.