toggle active script

ta.scm

#!/usr/bin/env guile
!#

;; Toggle symlink to current directory on and off in a directory of "active"
;; directories. Unless otherwise specified by a $ACTIVE_DIR environment
;; variable, the active directory is assumed to be located in ~/Active.

(use-modules (ice-9 ftw))

(define (symlink? path)
  (equal? (vector-ref (lstat path) 13)
          'symlink))

(let* ([active-dir (if (getenv "ACTIVE_DIR")
                       (getenv "ACTIVE_DIR")
                       (string-append
                         (passwd:dir (getpw (getlogin)))
                         file-name-separator-string
                         "Active"))]
       [pwd-name (basename (getcwd))]
       [actives (scandir active-dir)]
       [newpath (string-append active-dir
                               file-name-separator-string
                               pwd-name)])
    (cond
      [(and (member pwd-name actives)
            (symlink? newpath))
       (delete-file newpath)]
      [(member pwd-name actives)
       #f]
      ['else
       (symlink (getcwd) newpath)]))