Dynamically redirect the stdout of a child on Windows

Question

I've noticed a couple other questions about handling this, but all seem to suffer from:

• Not working on windows
• requiring the child to finish before retrieving output

What I would like to do is call a program (eg. tshark.exe) and process its output while it runs.

To date I have tried:

• Backticks
• Run3
• Proc::Reliable

all without any success. I could spend all day trying and failing to find a module which helps me with this (ie. I have spent all day), but I figured it might be better if I just asked if anyone knew of one.

Answer 1

Check out IPC::Run. IPC::Open2 and IPC::Open3 might meet your needs too.

Good luck!

Answer 2

You don't need a module. Just learn about the pipe forms of the open command -- these work just fine on Windows.

my $pid = open (my $cmd_handle, "tshark.exe @options |");
# on success, $pid holds process identifier of the external command.

while (<$cmd_handle>) {
    # sets $_ to next line of output.
    # Will block until a line of output is ready.
    # Is  undef  when the command is complete.

    ... process $_ ...
}
close $cmd_handle;   # waits for command to complete if it hasn't completed yet