Note: Linux is case sensitive, most of the commands are in lower case
Print working directory shows the current directory
pwd
Make a Directory
mkdir <directory>
Change into directory
cd <directory>
List of files & directories
ls
ls -l
Create an empty file
touch <filename>
The syntax of linux command
[optios]
touch
find
grep
Whenever you create a user a group with the same name is created.
sudo adduser testone
A group name with testone is created by default.
If you want to create the user in existing group, use:
sudo adduser <username> --gid <group_id_of_existing_group>
To run any command with superuser access, prefix sudo to the command
ex: sudo apt-get update
To login as a diferent user/ swith user
su - <username>
To see the list of groups to which the current user belongs to.
groups
List of all users and their details
/etc/passwd
Add user
sudo adduser <username>
Add Group
sudo addgroup <groupname>
Add user to a group
sudo usermod -aG <groupname> <username>
Not every user has a sudo permission. User has to be part of /etc/sudoers file
d rwx r-x r-x baddi baddi
r - Read - 4 w - Write - 2 x - eXecute - 1
- NoPermissions - 0
rwx r-x r-x 7 5 5
--- 0 r-- 4 r 5 rw- 6 rwx 7
774
- r-- --- --- 1 baddi baddi 1696 Mar 5 10:07 4 0 0
Change Permissions on a file
chmod xxx <filename>
chmod 750 testfile
Change the permissions a folder and it's contents
chmod -R 750 <foldername>
Change ownership of a file
chown <newowner> <filename>