##################################################################
#
# TRAVERSE_LINKS.sh
#
# Recursively traverse all inherited hyper-links
# of type LINK_TYPE.  Return a list of elements that are connected
# to the element via the LINK_TYPE.  Either return the children only,
# the ancesstors only, or both.  Always return the passed in element
# first.
#
# Author: Charles W. Clarke III  charles@tbi.com
# Date:   Sep. 17, 1996
####################################################################

USAGE: $SELF VOB_ELEMENT LINK_TYPE DIRECTION{child, parent, both} [ 
TEMP_FILE ]

TRAVERSE_LINKS.sh uses it own internal temp_file if non is given and it
cleans-up (removes) the file when done.  If a file is passed in then that
one is used and the caller is responsible for cleanup.  The output itself
can be used directly or piped to a command or file.

This is useful when link types need to be traversed to determin the scope
of a change.  For example if you had files linked together that were to be
changed together, you might link them with a "Force_Change" hyperlink, (If
I checkout this ... also checkout that).  Without worrying about previous
relationships or file-types one could in a post checkout trigger traverse
the links in on of the directions and checkout the connected list.

(i.e. cleartool co -nc `TRAVERSE_LINKS.sh foo.c Force_Change both` )


In the case of "---->" is a hyperlink of HLINK_TYPE "Force_Change"

     (foo.c)   ---->   (foo.h)   ---->   (foo.doc)   ---->   (foo.req)
         |
         ---->   (bar.c)   ---->   (bar.h)   <----   (bar.sh)


TRAVERSE_LINKS.sh bar.c Force_Change parent

   returns:
               bar.c
          foo.c

TRAVERSE_LINKS.sh bar.c Force_Change child

   returns:
          bar.c
          bar.h

TRAVERSE_LINKS.sh bar.c Force_Change both

   returns:
          bar.c
          foo.c
          foo.h
          foo.doc
          foo.req
          bar.h
          bar.sh
     
Either of the following will also place the output in SOME_FILE

     TRAVERSE_LINKS.sh bar.c Force_Change both SOME_FILE
     TRAVERSE_LINKS.sh bar.c Force_Change both > SOME_FILE

 The output can also used in other commands.

     cleartool ci `TRAVERSE_LINKS.sh bar.c Force_Change both`