Using screen to detach long running process from current session

Sometimes we want to execute a program which is more heavy and time consuming or maybe to compile something which is again – time consuming. Starting such a process from our current session is not the best decision because we can’t terminate the session and have to wait the process to finish. Using SSH is even more risky because the SSH session may be interrupted and this will terminate our work. This is more painful if you have been waited for hours to execute a program and your SSH session goes down few minutes before you complete execution.

Here GNU Screen comes to help.

… is useful for dealing with multiple programs from a command line interface, and for separating programs from the session of the Unix shell that started the program, particularly so a remote process continues running even when the user is disconnected.

To install screen use your operating system package manager. In my case the following command do that:

sudo apt-get intall screen

Next step is to start screen. Just run screen from the termina:


Now you’ve started a virtual console. You start your long running process here and instead waiting to complete, just detach the virtual terminal. To do that press CTRL + A and then D. This will detach the process and return you to your main session.
Now let’s list all detached screens:

scree -ls

The output should be similar to the following:

$ screen -ls
There is a screen on:
20855.pts-0.pi2 (02/11/2018 12:20:27 PM) (Detached)
1 Socket in /var/run/screen/S-pi.

To open again the detached screen run the following:

screen -r 20855.pts-0.pi2

Finally, but also important to know is how to close already started screen. To do that just type exit or press CTRL + D. This will terminate your current screen. I think that’s the most important you should know about screen. This tool is very handy and useful, so use it.

Multiple files rename

It is often necessary to rename multiple files, adding an index at the end of the name or completely change the name of the file. This is an easy task with bash, just one single line command:

count=0; for i in *.jpg; do let "count++"; mv "$i" "My Pictures - $count.jpg"; done;

Public share on Samba and Raspbian with write privileges

This is a quick and dirty tutorial how to setup a public share on Samba under Raspbian with write privileges for everyone.

1. Install packages below:

apt-get install samba
apt-get install samba-common
apt-get install samba-common-bin

2. Add the “pi” user to Samba using the command below:

smbpasswd -an pi

3. Modify /etc/samba/smb.conf to create the share.

comment = Downloads
path = /home/pi/storage/Downloads
browseable = yes
writeable = yes
guest ok = yes
guest only = yes
guest account = pi
force user = pi
force group = pi

The “path” parameter is used to specify the location of the share. Make sure /home/pi/storage/Downloads exists and it’s owned by the pi user.

4. When you are done just restart Samba.

/etc/init.d/samba restart

5. Take a beer and start testing