Important Bash Commands Used in Google IT Support Specialization

bash-commands.txt

Week 1:

1. ls /		or 		ls /home					-list all

2. ls --help 									-help menu

3. man ls										-more than help

4. ls / -l										-properties with longlist

5. ls / -l -a									-hiddden files

5. pwd											-print working directory

6. cd /home/ABShetty							-change directory

7. cd ..										- moves one lvl up

8. cd ~											- opens default user space

9. mkdir folder_name							- make folder(space not allowed)

10. mkdir 'folder name'    or
	mkdir  my`\ folder\ name					-(back slash \)
	
11. history  or ctrl+ r	or arrow keys			-recent commands list

12. cp *.jpeg /home/ABShetty				    -wildcard selection 
	cp -r 'folder-name' path 
	
13. mv file_name new_filename   				-rename
	mv filename path							-move( use wildcard)
	
14. rm -r foldername								-delete recursively

15. cat /filename								-opens entire file_name

16. less /filename 								-just 1 page,with more option below	
	g (moves to beginning)
	G (end)
	arrow keys and page up and down
	/word_u_want_to_search						-searches word in that opened txt file
	q (quit)
	
17. head /filename 								-1st 10 lines
	tail /filename								-last 10 lines by default
	
18. nano filename								-lightweight editor

19. grep search_word file_name					-searches for word

20. echo some_words > filename						-creates file & writes
	(echo boli > dog.txt)
	(echo maga >> dog.txt)							- (>>  append) not overwrite,it updats
	
21. ls /dir/fake_dir 2 > error.txt				-redirects error to file
	(dev/null unexited folder,used to filter error)
	
22. command | another_command						-concatinates commands


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week 2:

1. sudo cat /etc/sudoers							-to access restricted files

2. su user_name										-substitute user, defaults to root user.

3. cat /etc/group									-show groups.

4. cat /etc/passwd									-shows users

5. passwd user_name									-changes psswd

6. sudo psswd -e user_name 							- (e  expire flag)force passwd change.

7. sudo useradd user_name							-add user

8. sudo userdel user_name							-delete user

9. chmod ugo+rwx filename 								- permission setting( symbolic format)
	( u-user  g-group  o-others
		r-read  w-write  x-execute) 
		
10.	chmod 754 filename											-using octals: 
	( 7 -> 111 , order-rwx  ,  1=true 0-false					-user has all permissions
		5 -> 101 , 												- group has only read and execute
			4 -> 100 , 											- others had only read.
			
11. sudo chown owner_name filename 						- change owner of file

12. sudo chgrp group_name file_name						-changing group owner for the file

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1. sudo dpkg -i atom-amd64deb  							-debian pkg manager, i for install

2. sudo dpkg -r atom 									-removes pkg

3. uname -r 											-

4. sudo apt full-upgrade								-including dependencies for all pckages

5. apt update  & apt upgrade 							-for single pkg

6. Diskpart												-tool for partition

7.  list disk 											-lists all partitions
	select disk 1										- selects 1st one
	clean												
	create partition primary							-creates another partition
	select partition 1
	active												-make is as active to use
	format FS=NTFS label=my-drive quick					- formates file system NTFS with quick flash
	
8. sudo parted -l 										- lists disks

	sudo parted /dev/sdb 								-starts using /dev/sdb
	mklabel gpt
	print
	mkpart primary ext4 1MiB 5GiB						-creating partition with ext4
	quit
	sudo mkfs -t ext4 /dev/sdb1							-changes to ext4
	sudo mount /dev/sdb1 /my_usb/						-make it to use
	sudo unmount /dev/sdb1								-unmount
	sudo blkid											- shows UUID for block device IDs
	sudo mkswap /dev/sdb2								-swapping
	sudo swapon /dev/sdb2								- command to swapon
	
9. ln -s file_name softink_filename						-creating softlink for file 

10. notepad.exe file_1_shortcut.lnk						-creating shortcut
	mklink file_1_symlink file_1.txt					-making symbolic link
	notepad.exe file_1_symlink
	mklink /H file_1_hardlink file_1.txt				-making hardlink
	
11. fsutil query c:										- self healing disks

12. chkdsk /F D: 										- checking thumbdrive

13. sudo fsck /dev/sda 									- file system chek, but harmfull

14. ps -x 												- prints all processes

15. ps -ef 												- prints process with more fields
	ps -ef | grep chrome								- searches for particulat one
	
16. ls -l /proc 										- shows process with permissions etc/group

17. kill -KILL 10392 									-kills process with id (absolutely kill)

18. uptime 												- shows load avg

19. lsof 												-lists open files and what process are using them

20. scp file_with_path username@ip_address 				-share file remotely over scp protocol

21. ls /var/log 										- prints log page

22. less /var/log/syslog | grep error					-particularly accesssing syslog to search error

23. tail -f /var/log/syslog 							-end part of syslog,new things are updated here

24. sudo dd if=/dev/sdd of=/desktop/my_usb_image.img bs=100M	- imaging usb drive to desktop as my_usb_image.img