Elisp: How to accumulate function return into a list

Question

I have this small snippet of Elisp code that decodes kernel traces:

(defvar projbase "/my/proj/base")
(setq my_shell_output
  (substring 
   (shell-command-to-string (concat "/home/demetra/scripts/eaddrs2line.sh "
                                    projbase " " <each-line> ))
   0 -1))

How to write an Elisp function that calls this snippet of code for each line in a region and accumulate the results in a list ? The return is of format "module-name function-name file-path/file-name line-num".

After this is done I can work on the next task to show the list in a helm buffer where going to each line will open the file-path/file-name at line-num.

Answer 1

A few functions that might be useful here:

• (buffer-substring-no-properties BEG END) :: collect the buffer contents between BEG and END, two locations in the buffer (such as the beginning and end of a region), as a string
• (split-string STRING "\n") :: split STRING into a list of strings, broken at each linebreak
• (mapcar FUNCTION LIST) :: apply the function FUNCTION to every element in a LIST, and collect the results in a list.

In your case, something like this:

(mapcar (lambda (X) <SHELL-COMMAND-TO-STRING on X>)
        (split-string (buffer-substring-no-properties BEG END) "\n"))

Replacing <SHELL-COMMAND-TO-STRING on X> with the appropriate code. You'll still need to figure out how to get the values of BEG and END (maybe using (interactive "r")), and also you'll need to store/use the list returned by the mapcar.