To launch Vim and have a command executed as soon as it starts, prefix the command with a + and pass it as an argument. For example:

vim +digraphs

This is equivalent to doing :digraphs as soon as Vim starts. Commands can be chained as well. Say you have XtermColorTable installed:

alias colortable='vim +XtermColorTable +only'

Executing colortable in your shell will launch Vim showing a color table occupying the full-window instead of the plugin’s default vertical split, thanks to :only.