That output is being sent to STDERR rather than STDOUT. You can easily merge the two using open3 while still avoiding to spawn a needless shell. 

use IPC::Open3 qw( open3 );

my @command = qw( plink -ssh -pw passwd user@host -batch exit );

open3(\*CIN, \*COUT, \*COUT, @command);
close CIN;
    
my $xs = <COUT>;
print "the output is :".$xs;
close COUT;

[download]

Note that the order of open3's first two argument is different than open2's.

In reply to Re: assign open2 output to variable by ikegami
in thread assign open2 output to variable by adrivez

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