Learning Linux at University

I had to learn more about Linux at the university and so far I have learned couple of handy things.

1. You can configure nano settings with .nanorc file
2. Add alias commands to  .bash_aliases
3. Make some ALIAS. ls --color=auto for ls
4. Alias O for ls -latr listing all files in order, newest at bottom.
5. SCP files with scp filename username@host:/Where in remote
6. ssh-keygen -t RSA -b 4096 Generates ssh keys
7. ssh-add starts ssh-agent until computer is shutdown. 
8. Adding id_rsa.pub file content to authorized_keys in server allows ssh without typing password
9. in ~/.ssh create config file without file extension and set ssh configs. Like:
   Host NAME
       HostName nikiahlskog.com
       User USERNAME
       Identityfile ~/.ssh/id_rsa.pub
   Then you can just use ssh name for example.
10. RSYNC. It copies only changed files. Very handy! use it like: rsync --progress filename user@server:dir handle -a copies folder content
11. Crontab. Using crontab -e is dangerous. Because crontab -r empties whole table and there is no undo. Create folder for cronjobs and create file for example cron.tab add your job to the file for example: 0,30 * * * * echo `date +%Y-%m-%H\ %k:%M:%S` cron job done then add this file to crontab with crontab ~/cronjobs/cron.tab see all your cron jobs with crontab -l to remove cronjobs juse handle -e

Mount shared folder on Virtualbox. Windows host, linux guest.

To mount / share a folder between host and guest OS first create a folder in windows which you want to share.

For example: C:\myshare

Then assign it from the virtualbox settings-->shared folders-->+ icon: set folder path, tick Auto-Mount

Then boot up your guest os. Create a folder where you want to point the host os folder, for example /~share/. Then launch terminal and type:

sudo mount -t vboxsf myshare ~/share/

Then you should see items inside that folder.

OpenVpn save Username and Password to a file.

So I have created ShellScript which opens VPN connection but everytime it asks my password and I wanted to automate this. So do the following:

Inside your vpn key folder should be file called config.opvn or something that ends with .ovpn. Open it up and look for auth-user-pass if your file doesn't contain this add it to the bottom. Right after it add one space and filename.txt like this:

auth-user-pass vpnpass.txt

Then inside the same folder where your .ovpn file is add new file called vpnpass.txt and insert your username and password separated with enter. Like this:

myusername
mypassword

Save both files and now your VPN shouldn't ask password or username.