Three suggestions for your open:

• Use the three argument version
• Use lexical filehandles
• Use or not || for control flow.

open my $inputFH, '<', $pathToFile or die "Can't open $pathToFile for 
+reading.  Reason given = $!\n";
open my $outputFH, '>', $pathToFile2 or die "Can't open $pathToFile2 f
+or writing.  Reason given = $!\n";
while ($line = <$inputFH>)
{
    print $outputFH "Foo $line Baz\n";
}
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Edit: Writing to a file opened for reading was silly.