Basic Linux Commands

Question 1

ls - List directory contents - Basic Linux Commands

Answer 1

• Lists files, directories
• For long output, pipe through more: > ls -l | more
(use q or Ctrl-c to exit)

Question 2

grep - Find a text in a file - Basic Linux Commands

Answer 2

• grep PATTERN [FILE]

* > grep failed auth.log

Question 3

cd - Change current directory - Basic Linux Commands

Answer 3

• Nearly identical to Windows command line
• Forward slashes instead of backward
• cd
• > cd /var/log

Question 4

shutdown - Shut the system down - Basic Linux Commands

Answer 4

• sudo shutdown 2
  
  • Shuts down and turns o the computer in two minutes
• sudo shutdown -r 2
  
  • Shuts down and reboots in two minutes
• Ctrl-C to cancel

Question 5

pwd - Print Working Directory - Basic Linux Commands

Answer 5

• Displays the current working directory path

* Useful when changing directories often

Question 6

passwd - Change a user account password - Basic Linux Commands

Answer 6

• passwd [username]

Question 7

mv - Move (rename) a file - Basic Linux Commands

Answer 7

• mv SOURCE DEST

* > mv first.txt second.txt

Question 8

cp - Copy a file - Basic Linux Commands

Answer 8

• cp SOURCE DEST

* > cp rst.txt second.txt

Question 9

rm - Remove files or directories - Basic Linux Commands

Answer 9

• Does not remove directories by default

* Directories must be empty or must be removed with -r

Question 10

mkdir - Make a directory - Basic Linux Commands

Answer 10

• mkdir DIRECTORY

* > mkdir notes

Question 11

chmod - Change mode of a file system object - Basic Linux Commands

Answer 11

• r=read, w=write, x=execute
• Can also use octal notation
• Set for the file owner (u), the group(g), others(o), or all(a)
• chmod mode FILE
• > chmod 744 script.sh

Question 12

chown - Change file owner and group - Basic Linux Commands

Answer 12

• sudo chown [OWNER:GROUP] file

* > sudo chown professor script.sh

Question 13

iwconfig - View or change wireless network configuration - Basic Linux Commands

Answer 13

• Requires some knowledge of the wireless network

* iwconfig eth0 essid studio-wireless

Question 14

ifconfig - View or configure a interface and IP configuration - Basic Linux Commands

Answer 14

•ifconfig eth0

Question 15

ps - View the current process - Basic Linux Commands

Answer 15

• Similar to the Windows Task Manager
• View user processes - ps
• View all processes - ps -e | more

Question 16

su - Become a super user - Basic Linux Commands

Answer 16

• You continue to be that user until you exit

Question 17

sudo - Execute a command as the super user - Basic Linux Commands

Answer 17

• Only that command executes as the super user

Question 18

apt-get - Advanced Packaging tool - Basic Linux Commands

Answer 18

• Handles the management of application packages

* > sudo apt-get install wireshark

Question 19

vi - Visual mode editor - Basic Linux Commands

Answer 19

• Full screen editing with copy, paste, and more
• vi FILE
• > vi script.sh
• Insert text - i
• Exit insert mode with Esc
• Save (write) the file and quit vi - :wq

Question 20

dd - Convert and copy a file - Basic Linux Commands

Answer 20

• Backup and restore an entire partition
• > dd if= of= [Options] • Creating a disk image
• > dd if=/dev/sda of=/tmp/sda-image.img
• Restoring from an image
• > dd if=/tmp/sda-image.img of=/dev/sda