实际上，正确的写法是:

Actually, the proper way to write this is:

#!/usr/bin/perl
$cmd = 'lsss';  
my $out=qx($cmd 2>&1);
my $r_c=$?;
print "output was $out\n";
print "return code = ", $r_c, "\n";

如果没有错误，您将得到一个"0"，如果有错误，您将得到一个"-1".

You will get a '0' if no error and '-1' if error.