Basic Linux Commands

[MrGrj]

mkdir– make directories

Usage: mkdir [OPTION] DIRECTORY…

eg.

mkdir lhn

ls– list directory contents

Usage: ls [OPTION]… [FILE]…

eg.

ls

,

ls *l

,

ls lhn

cd– changes directories

Usage: cd [DIRECTORY]

eg.

cd lhn

pwd*- print name of current working directory

Usage: pwd

vim– Vi Improved, a programmers text editor

Usage: vim [OPTION] [file]…

eg.

vim lhn.txt

cp – copy files and directories

Usage: cp [OPTION]… SOURCE DEST

eg.

cp sample.txt sample_copy.txt

cp sample_copy.txt target_dir

mv– move (rename) files

Usage: mv [OPTION]… SOURCE DEST

eg.

 mv source.txt target_dir

mv old.txt new.txt

rm* remove files or directories

Usage: rm [OPTION]… FILE…

eg.

rm file1.txt , rm *rf some_dir

find– search for files in a directory hierarchy

Usage: find [OPTION] [path] [pattern]

eg.

find file1.txt, find *name file1.txt

history– prints recently used commands

Usage: history

cat– concatenate files and print on the standard output

Usage: cat [OPTION] [FILE]…

eg.

cat file1.txt file2.txt

cat *n file1.txt

echo– display a line of text

Usage: echo [OPTION] [string] …

eg.

echo I love RST

echo $HOME

grep*- print lines matching a pattern

Usage: grep [OPTION] PATTERN [FILE]…

eg.

grep *i apple sample.txt

wc*- print the number of newlines, words, and bytes in files

Usage: wc [OPTION]… [FILE]…

eg.

wc file1.txt

wc *L file1.txt

sort– sort lines of text files

Usage: sort [OPTION]… [FILE]…

eg.

sort file1.txt

sort *r file1.txt

tar– to archive a file

Usage: tar [OPTION] DEST SOURCE

eg.

tar *cvf /home/archive.tar /home/original

tar *xvf /home/archive.tar

kill– to kill a process(using signal mechanism)

Usage: kill [OPTION] pid

eg.

kill *9 2275

ps– report a snapshot of the current processes

Usage: ps [OPTION]

eg.

ps

,

ps *el

who– show who is logged on

Usage: who [OPTION]

eg.

who 

,

who *b

,

who *q

passwd– update a user’s authentication tokens(s)

Usage: passwd [OPTION]

eg.

passwd

su– change user ID or become super*user

Usage: su [OPTION] [LOGIN]

eg.

su remo

,

su

chown– change file owner and group

Usage: chown [OPTION]… OWNER[:[GROUP]] FILE…

eg.

chown remo myfile.txt

chmod– change file access permissions

Usage: chmod [OPTION] [MODE] [FILE]

eg.

 chmod 744 calculate.sh

zip– package and compress (archive) files

Usage: zip [OPTION] DEST SOURSE

eg.

 zip original.zip original

unzip– list, test and extract compressed files in a ZIP archive

Usage: unzip filename

eg.

unzip original.zi

ssh– SSH client (remote login program)

“ssh is a program for logging into a remote machine and for executing commands on a remote machine”

Usage: ssh [options] [user]@hostname

eg.

ssh *X guest@10.105.11.20

scp– secure copy (remote file copy program)

“scp copies files between hosts on a network”

Usage: scp [options] [[user]@host1:file1] [[user]@host2:file2]

eg.

scp file1.txt guest@10.105.11.20:~/Desktop/

fdisk– partition manipulator

eg.

sudo fdisk *l

mount– mount a file system

Usage: mount *t type device dir

eg.

mount /dev/sda5 /media/target

unmount– unmount file systems

Usage: umount [OPTIONS] dir | device…

eg.

umount /media/target

du– estimate file space usage

Usage: du [OPTION]… [FILE]…

eg.

du

df– report filesystem disk space usage

Usage: df [OPTION]… [FILE]…

eg.

df

quota– display disk usage and limits

Usage: quota [OPTION]

eg.

quota *v

reboot– reboot the system

Usage: reboot [OPTION]

eg.

reboot

poweroff 

– power off the system

Usage: poweroff [OPTION]

eg.

poweroff

kate– KDE Advanced Text Editor

Usage: kate [options][file(s)]

eg.

kate file1.txt file2.txt

vim– Vi Improved, a programmers text editor

Usage: vim [OPTION] [file]…

eg.

vi hello.c

gedit* A text Editor. Used to create and edit files.

Usage: gedit [OPTION] [FILE]…

eg.

gedit

bg– make a foreground process to run in background

Usage: type ‘ctrl+z’ and then ‘bg ‘

fg– to make background process as foreground process

Usage: fg [jobid]

jobs– displays the names and ids of background jobs

Usage: jobs

sed* stream editor for filtering and transforming text

Usage: sed [OPTION] [input*file]…

eg.

sed ‘s/love/hate/g’ loveletter.txt

awk* pattern scanning and processing language

eg.

awk *F: ‘{ print $1 }’ sample_awk.txt

find* search for files in a directory hierarchy

Usage: find [OPTION] [path] [pattern]

eg.

find *name file1.txt

locate– find or locate a file

Usage: locate [OPTION]… FILE…

eg.

locate file1.txt

Linux File Permissions

• 3 types of file permissions – read, write, execute
  

• 10 bit format from ‘ls *l’ command
  

1 2 3 4 5 6 7 8 9 10

file type owner group others

eg. drwxrw*r** means owner has all three permissions, group has read and write, others have only read

permission

• read permission – 4, write – 2, execute *1
  

eg. rwxrw*r** = 764

673 = rw*rwx*wx

Edited January 18, 2015 by MrGrj