Set value of a variable to region text

Question

I would like to write a script where I can select some text as the region, extract the selected region as a string, modify it, and pass it to another program.

I am playing around with ielm and see that I can call (yank) to pull the region string into a register. How would I go about getting the region string into a variable though?

Answer 1

This code should do what you want:

(setq your-variable  (buffer-substring (region-beginning) (region-end)))

If you want a command, try this:

(defun my-set-var-to-selection (variable beg end)
  "Set VARIABLE to a string with the selected text.
You are prompted for VARIABLE."
  (interactive 
   (if (use-region-p)
       (list (intern (completing-read "Variable: " obarray 'boundp t))
             (region-beginning)
             (region-end))
     (error "No selection (no active region)")))
  (set variable (buffer-substring beg end)))

If you don't want to require VARIABLE to already be a variable (you want to allow any name as a variable) then remove the arguments 'boundp and t from the completing-read call.

If you want to use the region text even when the region is not active (no selection) then use just this as the interactive spec:

(interactive 
  (list (intern (completing-read "Variable: " obarray 'boundp t))
        (region-beginning)
        (region-end)))