Thanks for the help drieux.
I could have been more explicit in my question to have stated that
I want perl.script to exit quietly if there are no files on the
command line or if not invoked as the recipient of piped output.
I tested your code (I named the file test.input.source) and ...
Case 1.
As I understand it, <> operator will open all items in @ARGV allowing
one
to do a shell command line of
perl.script file1 file2 file3
and inside perl.script you only need
while (<>) { ... syntax to read all the files on the command line.
<> will also open STDIN if the perl script is invok
