UNIX® shells maintain the previous working directory in the variable
so it is easy to jump back to where you were previously dwelling:
$ cd $OLDPWD
This is a bit cumbersome to type, so this shortcut is provided:
$ cd -
(My then-classmate Carlos told me about this back in ’98).
Recently I learned that for commands other than ‘cd’, which is internal to the
shell, ksh and bash provide a tilde expansion for this
OLDPWD var, i.e.:
$ cd /srv/media/doc/science/cs/biblia/oreilly/lang/perl $ ls mastering* mastering_perl.pdf $ cd /this/other/place $ cp -a ~-/mastering_perl.pdf . # et voilà !