The Fit Long File Specification into Fixed Field routine takes a
    file specification, such as an OpenVMS RMS resultant name string,
    and shortens it (if necessary) so that it fits into a field of
    fixed width.

    Format

      LIB$TRIM_FILESPEC  old-filespec ,new-filespec

                         [,word-integer-width] [,resultant-length]

  Additional Information (explode) :

• Returns
• Arguments