Scripting with Bash Compact Course @ MPE Moritz August March 14 - - - PowerPoint PPT Presentation

Scripting with Bash

Compact Course @ MPE

Moritz August

March 14 - 16, 2017

Moritz August: Scripting with Bash Compact Course @ MPE, March 14 - 16, 2017 1

Part IV Working Remotely And More

Moritz August: Scripting with Bash Compact Course @ MPE, March 14 - 16, 2017 2

Working remotely - ssh, scp and tmux

ping

• ping hostname
• Useful to find out whether some machine is down or has no

connection.

Moritz August: Scripting with Bash Compact Course @ MPE, March 14 - 16, 2017 3

Working remotely - ssh, scp and tmux

ping

• ping hostname
• Useful to find out whether some machine is down or has no

connection. ssh and scp - security by encryption

• Developed 1995 to allow secure connections between computers
• ssh username@computername log in onto computername as

username

• scp -r * username@computername:<path_rel_to_home>
• scp *.txt username@computername:/<absolute_path>
• scp "username@computername:path/*.*"./ – copy all remote files

in folder path to current directory

• Quotes necessary for remote wildcards

Moritz August: Scripting with Bash Compact Course @ MPE, March 14 - 16, 2017 3

Working remotely - ssh, scp and tmux

Tunneling connections

gname @gate local rname @remote XY 22 XX ssh ssh 22

• You can ssh from local machine to gate
• You can (e.g.) ssh from gate to remote
• You cannot directly access remote
• Then use ssh for tunneling the connection

Moritz August: Scripting with Bash Compact Course @ MPE, March 14 - 16, 2017 4

Working remotely - ssh, scp and tmux

Tunneling connections

gname @gate rname @remote gname @gate local rname @remote XY 22 XX ssh ssh 22 local XX

8888

ssh 22 XY 22

• You can ssh from local machine to gate
• You can (e.g.) ssh from gate to remote
• You cannot directly access remote
• Then use ssh for tunneling the connection

ssh -L 8888: < remote >:22 <gname >@<gate > # then in other terminal scp -P 8888 file.txt <rname >@localhost:some/dir ssh -p 8888 <rname >@localhost

Moritz August: Scripting with Bash Compact Course @ MPE, March 14 - 16, 2017 4

Working remotely - tmux

• during a typical session, many terminals are used
• if working remote, this means opening many ssh connections
• for each login/logout, everything has to be closed/opened again
• tmux solves all these problems by creating virtual terminals
• tmux commands can be accessed by Ctrl+b
• Ctrl+b, % creates a new pane
• Ctrl+b, " splits pane into two panes
• Ctrl+b, x kills pane
• Ctrl+b, c creates new window
• Ctrl+b, & kill window
• Ctrl+b, <Arrow> switch pane
• Ctrl+b, <Number> switch window
• Ctrl+b, d detach from tmux
• tmux a attach to tmux

Moritz August: Scripting with Bash Compact Course @ MPE, March 14 - 16, 2017 5

Some more commands you should know

basename "this/is/the/path/to/a.file" dirname "this/is/the/path/to/a.file" time sleep 3 time for i in `seq 100000 `; do a=$[3*$i]; done users groups du -sh df -h ln -s <file > <link >

Moritz August: Scripting with Bash Compact Course @ MPE, March 14 - 16, 2017 6