iloveyii / linux

Linux commands and tips

Linux

Reset password

• Error : enter root password for maintenance
• Press shift as soons as system starts
• Advanced option > Goto normal Ubuntu line (with no recovery) > Press e
• Enter init=/bin/bash at the end of linux line (remove everything after ro first)
• Press F 10
• It will start in single user mode, reset required user's password and reboot

Reset Ubuntu password in Vmware

• To show boot menu for a longer time, locate the vmare directory and open the .vmx file in text editor
• Add the following at the end of the file, timeout is in milliseconds (make sure the vm machine is off else this change will be overwritten)

bios.bootDelay = "5000"

• Boot vmaware machine and press and hold shift key, select advanced > recovery > root
• If the file system is ready only use commamnd mount -rw -o remount /

Graphics

• Identify video card lspci | grep VGA
• Details sudo lshw -C video

Applications

• Add a custom launcher to dock
• First create a file ~/.local/share/applications/intellij.desktop with the following contents

#!/usr/bin/env xdg-open
[Desktop Entry]
Version=1.0
Terminal=false
Type=Application
Name=IntelliJ
GenericName=IDE
Exec=/home/alex/softwares/intellij/bin/idea.sh
Icon=/home/alex/softwares/intellij/bin/idea.svg

• List the dock apps gsettings get org.gnome.shell favorite-apps
• Set custom launcher in dock gsettings set org.gnome.shell favorite-apps "['org.gnome.Nautilus.desktop','intellij.desktop', 'org.gnome.Terminal.desktop', 'google-chrome.desktop', 'firefox.desktop', 'gnome-control-center.desktop', 'org.gnome.tweaks.desktop']"

Mount VM shared folder inside Ubuntu

• Share a folder from guest
• You can check the share folder inside guest as vmware-hgfsclient
• Create an empty directory inside projects/docker
• Mount it to a directory inside ~/projects/ by using command /usr/bin/vmhgfs-fuse .host:/docker /home/alex/projects/devops/docker/ -o subtype=vmhgfs-fuse,allow_other
• Unmount sudo umount ~/projects/devops

Ubuntu add SSH Keys

• Login to server with root
• Add new user adduser abc
• Add user to sudo group usermod -aG sudo abc
• Check that new user has sudo id abc
• Switch to new user sudo su - abc
• Recheck that new user has sudo, sud ls /root
• Make dir .ssh and add file nano .ssh/authorized_keys and paste your .ssh/id_rsa.pub key from your client computer
• You should be able to login without password ssh abc@host

Use existing user

• If you have a user login/password to a remote server, you don't need to use pass again and again
• Add it user ssh-copy-id ali@192.168.x.x, and I think before this you may need to ssh-keygen -t rsa -b 4096 -C "[e-mail]"