How can I make .vimrc read from an external file?

Solution 1:

in your main .vimrc file:

source otherVimScriptFilePath.vim

then just put your variable statement in that file:

" otherVimScriptFilePath.vim
let whoami = "user1"

Solution 2:

Using a try/catch

Since asking this question, I've come up with another use case for loading an external file: machine-specific tweaks.

Since I may or may not need to make tweaks on a given machine, I'm using a try/catch to load the external file; if there's no such file, I let it fail silently.

" If there are any machine-specific tweaks for Vim, load them from the following file.
try 
  source ~/.vimrc_machine_specific
catch
  " No such file? No problem; just ignore it.
endtry