pwd :- print working directory (To know where am i)
cd :- Change directory (To change folder)
cd .. :- to come back to old folder
cd ../.. :- To come back to two folders
cd /home/user/Dowmloads :- used to where ever you want (path)
cd ~ :- used to get back to home
cd - :- To go to your previous location
ls :- List (To know list of folders and files in folder)
clear :- To clear all the commands
touch :- Touch command is used to create file
mkdir :- used to make/create new folder
rm :- used to remove file
rmdir :- remove directory (used to delete empty dir)
rm -rf :- used to delete any folder/file
mv :- To move file or directory one folder to another
state :- To show details of file or folder
cp :- used to copy file
cp -r :- to copy dir recursively
cat :- Concatenate (To dispay what inside the file)
nano :- used to edit file
vi/vim :- used to edit file
./ :- used to execute any file
sh/bash :- used to execute shell file
history :- used to look commends what we use till now
Package managers
CentOS/Redhat/Amazon Linux :- We use yum package managers. rpm is the supportable files/forma
ubuntu/debian --> apt or apt-get package managers
sudo yum install <package name(s)> :- Install packages in
sudo yum update <package names> :- To update the packages
sudo yum remove <package name> :- To remove packages
sudo yum downgrade <package name> :- To downgrade to the previous version.
rpm -qa :- List all the packages which are installed
rpm -qa --last :- List all the packages which are installed along with the date
apropos :- used to search for command
ls --help:- What is used for "ls" command
man man :- Used to open manual
man cp :- To show all cp commands and manual
pipe(|) :- pipe is used to give two or more commands at same time
cat file | sort :- To get list alphabatic order
cat file | sort | uniq :- To (do not repete same line)
cat file | head -3 :- To show first three lines
cat file | tail -4 :- To show last four lines
cat file | wc -l :- To show no of lines
grep is used to search for string/content in the file
grep <word> <file name> :- search for content in the file
grep -r <words> <file name> :- adding -r is to search any thing in dir
grep -i <word> <file name> :- case sensitive upper/lower words
grep -A <word> <file name> :- to disply after the matched line
grep -B <word> <file name> :- to disply before the matched line
grep "Tayota" file :- To know Tayota is there are not in the file
grep "Tayota" file -n :- To know in which line Tayota is present
grep "Tayota" file -v :- To show all lines except Tayota
cat file | grep "Tayota" | tee file1 | wc :-
used to copy text to file and show word count.
aws configure --profile // to create profile
aws configure list-profiles // to list the profiles
export AWS_PROFILE= // swith b/w profiles
aws sts get-caller-identity // to know the current profile
cd /etc/ssh/ :- To change folders in vm
ls -l :- To show files and folders in vm
sudo passwd ec2-user
sudo nano sshd/ssh_configure
cat ssh/sshd (change Profile password - Yes)
sudo systemctl reload sshd/ssh
change permissions of a file or dir
chmod <perm> <file or dir> :- To change the permissions.
chmod -R <perm> <dir name> :- Apply/change the permissions to a dir and its content.
chmod rwx <filename> to add permissions
chmod -rwx <directoryname> to remove permissions.
chmod x <filename> to allow executable permissions.
chmod -wx <filename> to take out write and executable permissions.
Note that “r” is for read, “w” is for write, and “x” is for execute.
0 = No Permission
1 = Execute "X"
2 = Write "W"
4 = Read "R"
-rwxr-xr-x :- 755
- rwx rw- r-x r-- -wx -w- --x
7 6 5 4 3 2 1
change the owner of a file/dir:
chown <owner to change> <file or dir>
id <username> :- To check if a user is present in your system.
cat /etc/passwd :- To list all the users.
sudo chown -R devops dir5/ :- To change owner for all inside dir5