perl using open3 to write to STDIN and capture STDOUT and STDERR

Question

I'm using a Windows x64 machine and am trying to capture the STDOUT and STDERR streams from a command. I also have to write to the command's STDIN. I'm trying to use perl's IPC::Open3 for this, with no luck. I'm using the script posted here and the command as this script here. I of course replaced the $cmd variable with "perl test.pl" for Windows.

It's supposed to print 'StdOut!' and 'StdErr!', along with the pid, but I only get the PID. I don't know if it is because of my operating system, or because the thread is 10 years old (no biggie, Perl 5 is almost 18, right?). Another monk posted this script to fix any problems in the other one, but on my computer it never exits.

Can anyone give me a working example of using open3 to start a command in perl, write to its STDIN, and capture both its STDERR and its STDOUT?

ikegami ikegami · Accepted Answer · 2012-08-02T20:03:41

select only works for sockets in Windows; it doesn't work on pipes. You could create sockets instead and pass those to open3 instead of letting it create pipes for you (as seen here), but I suggest that you use a higher-level module such as IPC::Run instead. open3 is a rather low-level function.

perl using open3 to write to STDIN and capture STDOUT and STDERR

1 Answers