>perl out.pl d.d

initial: fileno(*STDOUT) = 1
initial: fileno(*STDERR) = 2

redirected: fileno(*STDOUT) = 1
redirected: fileno(*STDERR) = 2


hello - this is contents of d.d

testing stdout capture 1
testing stderr capture
testing stdout capture 2


>perl out.pl 

initial: fileno(*STDOUT) = 1
initial: fileno(*STDERR) = 2

redirected: fileno(*STDOUT) = -1
redirected: fileno(*STDERR) = -1
hello - this is $captured_output

testing stdout capture 1
testing stdout capture 2