Proper perl execution

Don't use
   # running program
   system("/bin/program arg1 arg2");
   
   # getting the output
   $output =  `/bin/ls -lR directory`;
   open(FOO, "/bin/ls -lR directory|");
   
   # sending input
   open(FOO, "|/usr/bin/nc webserver 80"); 
   
Do use
   system "/bin/program", "arg1", "arg2";
   
   # getting output
   open(FOO, '-|') || exec '/bin/ls', '-lR', 'directory';
   
   # sending input
   open(FOO, '|-') || exec '/usr/bin/nc', 'webserver', '80';