in reply to IO::Handles ... any good?

The easy way: 
 my $file = $ARGV[0] || die "Synopsys: $0 <filename>" ;
 print "This is the filename to be processed: $file\n";

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Re^2: IO::Handles ... any good?
by jwkrahn (Abbot) on Mar 22, 2009 at 19:20 UTC

    The  || operator has higher precedence than the  = operator so you should either enclose the assignment in parentheses: 

    ( my $file = $ARGV[0] ) || die "Synopsys: $0 <filename>" ;

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    or use the lower precedence  or operator: 

    my $file = $ARGV[0] or die "Synopsys: $0 <filename>" ;

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    Also, that test will fail if you have a file named  '0'.

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      so you should either enclose the assignment in parentheses:

      Why? The intention is to check $ARGV[0], so || is perfectly acceptable.

      There's is a problem with both your solution and your parent's: It won't work for a file named "0". The following will, however: 

      my ($file) = @ARGV
   or die(...);

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