!! +var+ +string+
tit:rename
type:$type_both
syntax:!rename ``f''
mean:Changes the reference to a file ``f'', such as a graphics file reachable by direct http, \
  into one with a different name using the method <span class="tt">!getfile</span>.\
  <p>\
  This command is useful with exercises where important information is carried\
  by multimedia files (pictures, audios, movies). It can be used to hide the\
  name of the multimedia file that otherwise would give clues to the solution\
  of the problem.\
  </p><p>\
  The renamed file must be located within the module, and the filename ``f'' should start \
  with ``&#36;module_dir''.\
  </p><p>\
  The command returns a string which is the new URL. The file is not\
  effectively copied or renamed on the server.\
  </p>
