Shell Commands

sed

Insert content from file after pattern:

sed -i -e "/pattern/r${file}" target.txt

Replace pattern with content from file:

sed -i -e "/{pattern/r${file}" -e "d}" target.txt

Reverse Tunneling

Definitions:

WS

Workstation, connects to the tunnel.

JS

Jump server, can be the same host as WS if directly accessible. sshd_config must have AllowTcpForwarding yes and GatewayPorts yes.

RS

Remote server, establishes the tunnel.

On RS establish the tunnel to JS:

ssh -R <JS port>:<RS iface adress>:<RS port> [<JS user>@]<JS adress> # i.e. for forwarding ssh: ssh -R 2222:0.0.0.0:22 [email protected]

On WS connect to JS, for ssh this may look like:

ssh -F/dev/null -p 2222 [email protected]