How do I check if I've been run in read-only mode (-R) in vimrc

Question

In my .vimrc, I'd like to be able to check if I've been run either by vim -R or view. If so, I plan to either disable or delay some plugins from loading to speed up the times when I quickly want to look at a file.

:args and argv() only seem to show me which files I wanted to edit, not all the command line flags.

Checking if &readonly almost works. If I have this:

if &readonly
    echo "read only"
else
    echo "not read only"
endif

Then I get read only echoed when I execute view or vim -R, but if I do either view ~/.vimrc or vim -R ~/.vimrc then I get not read only. Very strange.

Thanks!

Answer 1

Vim's program name (eg view) can be detected with the v:progname variable. This doesn't solve checking for vim -R, but it does allow you to use this variable in a condition in your .vimrc and potentially improve the efficiency of your config. For example:

if v:progname ==? 'view'
  " Do something
endif