KubeOps Linux CheatSheet

This is Day to Day Work Linux Cheatsheet for Software Engineers.

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Directory Commands

Name	Command
Change Directory	cd /<directory_path>
Change Directory to Previous	cd ..
Create Directory	mkdir <directory_name>
Create Directory with Parent	mkdir -p <parent_directory_name>/<directory_name>
Remove Directory	rm -r <directory_name>
Remove Directory without prompt	rm -rf <directory_name>
Remove empty Directory	rmdir <directory_name>
Copy Directory	cp -r <directory_name> <destination_path>
Move Directory	mv <directory_name> <destination_path>

Search Commands

Name	Command
Search files in a directory	find <directory_name> -name <file_name_pattern>
Search files in a directory with case-insensitive	find <directory_name> -iname <file_name_pattern>
Search files in a directory and execute command on it	find <directory_name> -name <file_name_pattern> -exec <command>
Search text in file	grep <text> <file_name>
Search text in file with line numbers	grep -n <text> <file_name>
Search text in file with case-insensitive	grep -i <text> <file_name>
Search text in file for all patterns given	grep -e <text> <file_name>
Search multiple text with case-insensitive and all pattern given	grep -ie <text1> <file_name> -ie <text2> <file_name> -ie <text3> <file_name> -ie <textn> <file_name>
Search file for any lines that don't include the content	grep -v '<content_pattern>' <file_name>

Pipes

Name	Command
Send stdout of cmd1 to cmd2	cmd1 | cmd2
Send stderr of cmd1 to cmd2	cmd1 |& cmd2

File Commands

Name	Command
Show content of the file	cat <file_name>
Create a file with content	cat <<EOF > <file_name> #!/bin/bash <content> EOF
Create an empty file	touch <file_name>
Remove file	rm <file_name>
Remove file without prompt	rm -f <file_name>
Copy file	cp <file_name> <destination_path>
Move file	mv <file_name> <destination_path>
Show first n lines of file	head -n <file_name>
Show last n lines of file	tail -n <file_name>
Keep showing last 10 lines of file	tail -f <file_name>
Show total line in a file	cat <file_name> | wc -l
List files in current directory	ls
List files, hidden files in current directory	ls -a
List files in current directory with their permissions and sizes	ls -l
List files in current directory with their permissions, sizes, units	ls -lh
Paginate the content of file	cat <file_name> | less
Create symbolic link to source file in current directory	ln -s <file_name>
Create symbolic link to source file in directory	ln -s <file_name>
Extract .tar.gz file	tar -zxvf <file_name>
See the differences between files	diff <file_a> <file_b>

File Permissions Commands

Name	Command
Change file permission with permission number	chmod 755 <file_name>
Change directory permission with permission number	chmod -R 755 <directory_name>
Change directory permission with letters	chmod -R u+rw,g+r,o+x <directory_name>
Change file owner	chown <file_name>
Change file owner with user's login group	chown : <file_name>
Change directory and its content owner recursively	chown -R <directory_name>

File Permissions Numbers

Name	Command
4	read (r)
2	write (w)
1	execute (x)

Process Commands

Name	Command
Shows processes for the current shell	ps
View all the running processes	ps -A or ps -e
View all processes associated with the terminal	ps -a
View all processes associated with the terminal and show user	ps -aux
Kill specific process id	kill -SIGTERM <process_id> ...
Lists signal	kill -l
Kill all processes with specifies name	pkill <process_name>
Kill all processes with case-insensitive	pkill -i <process_name>
Kill specific running command	pkill -f <running_command_pattern>
Kill all processes with specific signal	pkill --signal <signal> <process_name>
Show dynamic real-time processes list of specific user	top -u <user>

Vi/Vim Command Shortcuts

To understand Vim well, we need to understand Vim editing modes. Vim has 6 basic modes which are:

Name	Description	Help page
normal	For navigation and manipulation of text. This is the default mode.	:help Normal-mode
insert	For inserting new text.	:help Insert-mode
visual	For manipulation of text selection.	:help Visual-mode
select	Similar to a visual mode, but with a more MS Windows-like behavior.	:help Select-mode
command-line	For entering editor commands - like the help commands (:help), quit (:q)	:help Command-line-mode
Ex-mode	Similar to a command-line mode but optimized for batch processing.	:help Ex-mode

Name	Command	Example
Edit a file	vi <file_name>
Enter an insert mode to insert new text	i
Insert a blank line under the current line and switch to an insert mode	o
Switch to an insert mode and move a cursor to the end of line (Append)	A
Copy the current line	yy
Paste copied text after the current cursor position	p
Delete the current line and switch to an insert mode (Change a line)	cc
Delete the current line and stay in an normal mode	dd
Delete from the current cursor position to the end of a word	dw
Delete before the current cursor position to the beginning of a word	db
Delete a character at the current cursor position and stay in a normal mode	x
Delete and switch to an insert mode from the current cursor postion to the end of line	C
Delete a character and switch to an insert mode (Substitute a character)	s
Move the cursor left	h
Move the cursor down	j
Move the cursor up	k
Move the cursor right	l
Go to the begining of the first line	gg
Go to the begining of the last line	G
Go to a line number	<row_number> + gg
Go to a column number	<column_number> + \
Search keyword	/ <keyword>
Search keyword with case-insensitive	/<keyword>\c
Move to the next found keyword after searching	n
Move to the previous found keyword after searching (invert of n)	N
Visual selection a character at the current cursor position	v
Visual selection the current line	V
Tab right	shift + .
Tab left	shift + ,
Repeat a last change	.
Undo change	u
Redo change	ctrl + r
Save and quit	:wq
Quit (The most important Vi/Vim command)	:q

Bash Commands

Name	Command
Show System	uname -a
Show Mounted File System	mount
Show System Date	date
Show Uptime	uptime
Show username	whoami
Show Manual Command	man <command>
Show History Command	history

Bash Shortcuts

Name	Command
Stop Current Command	CTRL + c
Sleep Program	CTRL + z
Search History	CTRL + r
Repeat Last Command	!!
Run the most recent command that matches with starting character(s) of string	!<string>

Bash Variables

Name	Command
Show Environment Variables	env
Show Value of Variable	echo $<VariableName>
Set Value of Variable	export $<VariableName> = <value>
Show Executable Search Path	$PATH
Show Home Directory	$HOME
Show Current Shell	$SHELL

Multiple Commands

Name	Command
Run command1 then command2	<command1> ; <command2>
Run command2 if command1 is successful	<command1> && <command2>
Run command2 if command1 is not successful	<command1> || <command2>

Network Commands

Name	Command
Display all network interfaces and IP addresses	ifconfig -a
Send echo requests to the target host to verify connectivity	ping <host>
Get who is information for domain	whois <domain>
Get DNS information for domain	dig <domain>
Reverse lookup host	dig -x <host>
Display name of server	hostname
Download file	wget <file>
Listing all listening connections ports	netstat -a

References

An A-Z Index of Linux command line: Link