Did you know that the Android mobile operating system was built upon a Linux kernel? Did you know that you can install apps like BusyBox and Terminal Emulator and use many basic Linux commands? You can! In order to learn how to use terminal emulator commands, you will need a rooted device and the proper apps, we have an article that discusses these apps in further detail and provides download links.

  • 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 India
    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 super­user
    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 [email protected]
  • 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 [email protected]:~/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
  • umount – 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] [input­file]…
    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. drwxrw­r­­   means owner has all three permissions,
    group has read and write, others have only read
    permission
  • read permission – 4, write – 2, execute ­1
    eg. rwxrw­r­­   = 764
    673    =   rw­rwx­wx