Check which ports are open to the outside world. Helps make sure that your firewall rules are working as intended.
One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.
Please try
#!/bin/sh
ed $1 << END
1,$ s/$/more data/
w
q
END
you may call the above script myshell and after you make it executable (chmod +x myshell), you may use it as:
./myshell myfile