Vim: sourcing based on a string

Question

I can't seem to find an answer to this in any of the numerous Vim scripting tutorials online. What I want to do is construct a file name of a script from environment variables and then source it. And I want to do it in Vim.

If I were to do it in a shell I'd do something like this:

source ${HOME}/.vim/myscript_${FOO}.vim

How do I do it in Vim?

Answer 1

You can use the execute command:

:exec ":source " . $HOME . "/.vim/myscript_" . l:foo . ".vim"

Answer 2

Just :source works for me:

% export MYPATH='a/b/c'
% mkdir -p $MYPATH
% export MYFILE='temp.vim'
% cat > $MYPATH/$MYFILE
echo 'hello world'
^D
% vim
:source $MYPATH/$MYFILE
hello world

If you want to have some vim scripts automatically sourced though, just stick them in your ~/.vim/plugin/ directory, and they'll be loaded for you, without having to do it manually.

From :help expand-environment-var (which I got by doing :help environment and tab completing to the first likely result)

             *:set_env* *expand-env* *expand-environment-var*
    Environment variables in specific string options will be expanded.  If the
    environment variable exists the '$' and the following environment variable
    name is replaced with its value.  If it does not exist the '$' and the name
    are not modified.  Any non-id character (not a letter, digit or '_') may
    follow the environment variable name.  That character and what follows is
    appended to the value of the environment variable.  Examples: >
       :set term=$TERM.new
       :set path=/usr/$INCLUDE,$HOME/include,.
    When adding or removing a string from an option with ":set opt-=val" or ":set
    opt+=val" the expansion is done before the adding or removing.

I tend to find vim's built in help more useful than anything else, but it does take a while to get the knack of knowing what to look for.