       pushd [ arg ]
       pushd old new
       pushd +-n
              Change the current directory, and push the old cur-
              rent directory onto the directory  stack.   In  the
              first  form,  change  the current directory to arg.
              If arg is  not  specified,  change  to  the  second
              directory  on  the stack (that is, exchange the top
              two entries), or change to the value of HOME if the
              PUSHD_TO_HOME option is set or if there is only one
              entry on the stack.  If arg is  -,  change  to  the
              value  of  OLDPWD,  the  previous  directory.  If a
              directory named arg is not  found  in  the  current
              directory  and arg does not contain a slash, search
              each component of the shell parameter  cdpath.   If
              the option CDABLEVARS is set, and a parameter named
              arg exists whose value begins with a  slash,  treat
              its   value   as  the  directory.   If  the  option
              PUSHD_SILENT is not set, the directory  stack  will
              be printed after a pushd is performed.

              The second form of pushd substitutes the string new
              for the string old  in  the  name  of  the  current
              directory,  and  tries to change to this new direc-
              tory.

              The third form of pushd is equivalent to popd.
