sed ?

[Shutoku Shia]

I would like to know how to do the following with sed:
  1) how to use substitution and negation(!) in a sed script,
     for example, suppose I DO NOT want to apply the following
     substitution "s/foo/FOO/g" on line(s) for which "/^\/$/" apply.
  2) does anyone know of a sample sed script which allow one to modify
     a file, however, in this case, both the input file and the output
     file is the same file (input file does not refer to the instuction
     file -- i.e. sed script is NOT input file).

     In ex terms, what is the sed equivalent of,

     ex - junk <<EOF
       ex script
       ex script
       ...
       w
     EOF

Please send me email if you know solutions.  Thanks.

	Shutoku

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