Function: package-get-version
package-get-version is an autoloaded and byte-compiled function
defined in package.el.gz.
Signature
(package-get-version)
Documentation
Return the version number of the package in which this is used.
Assumes it is used from an Elisp file placed inside the top-level directory of an installed ELPA package. The return value is a string (or nil in case we can't find it).
Probably introduced at or before Emacs version 27.1.
Source Code
;; Defined in /usr/src/emacs/lisp/emacs-lisp/package.el.gz
;;;###autoload
(defun package-get-version ()
"Return the version number of the package in which this is used.
Assumes it is used from an Elisp file placed inside the top-level directory
of an installed ELPA package.
The return value is a string (or nil in case we can't find it)."
;; In a sense, this is a lie, but it does just what we want: precompute
;; the version at compile time and hardcodes it into the .elc file!
(declare (pure t))
;; Hack alert!
(let ((file (or (macroexp-file-name) buffer-file-name)))
(cond
((null file) nil)
;; Packages are normally installed into directories named "<pkg>-<vers>",
;; so get the version number from there.
((string-match "/[^/]+-\\([0-9]\\(?:[0-9.]\\|pre\\|beta\\|alpha\\|snapshot\\)+\\)/[^/]+\\'" file)
(match-string 1 file))
;; For packages run straight from the an elpa.git clone, there's no
;; "-<vers>" in the directory name, so we have to fetch the version
;; the hard way.
(t
(let* ((pkgdir (file-name-directory file))
(pkgname (file-name-nondirectory (directory-file-name pkgdir)))
(mainfile (expand-file-name (concat pkgname ".el") pkgdir)))
(when (file-readable-p mainfile)
(require 'lisp-mnt)
(with-temp-buffer
(insert-file-contents mainfile)
(or (lm-header "package-version")
(lm-header "version")))))))))