das rockbüro

If you use emacs on a mac, you have two different options: Using Carbon Emacs (or AcquaMacs) or use a command line emacs. The administration of two different emacs configurations, however, is annoying. At least.

Therefore, I always had an alias in my ~/.profile file:

alias emacs="open -a /Applications/Emacs.app"

The alias starts the GUI Emacs when emacs is started in a terminal window.

So far so good. But: console emacs creates a file, if you give a nonexisting file as argument. The open command, however, does not start Emacs.app if the file does not exist.

The solution:

File ~/.profile:

function start_emacs {
    FILE=$1
    if [ ! -e "$FILE" ]
    then
	touch $FILE;
    fi;
    open -a /Applications/Emacs.app $FILE
}

alias emacs="start_emacs"

When you call emacs on the command line, it invokes a function defined in the .profile. The function checks, whether the file exists. If it does not, it touches it. Afterwards, Emacs.app is launched.

(If you think of putting all this together in an alias definition: don’t. Variable names are expanded when the alias is defined, not when it is used.)