REVIEW OF FREQUENTLY USED UNIX COMMANDSGENERAL COMMAND SYNTAX:$ command –[options] DISPLAYING CONTENTS OF A DIRECTORY:$ ls (simple form)$ ls –l (long form)$ ls –la [long form and all files including hidden files. (hidden filenames begin with a dot)]DISPLAYING FILENAMES THAT HAVE COMMON START/END:$ ls –l chapter* (shows filenames like chapter01, chapter02, chapterfour, etc)$ ls –l *.txt (shows filenames like book.txt, song.txt, readme.txt, etc)DISPLAYING CONTENTS OF ONE OR MORE FILES:$ cat song.txt$ cat song.txt book.txt readme.txtCOPYING/MOVING/RENAMING FILES:$ cp file1.txt file2.txt (copies! file1.txt also exists)$ mv file1.txt file2.txt (renames! file1.txt NO longer exists)$ mv file1.txt docs/year2005/file1.txt (moves! from current directory to docs/year2005 directory)$ mv file1.txt docs/year2005/file2.txt (moves and renames! from current directory to docs/year2005 directory)CREATING DIRECTORIES:$ mkdir year2005 year2006$ mkdir year2005/docs year2005/picsCREATING/MODIFYING FILES USING pico EDITOR:$ pico year2005/docs/myfile.txt pathname type inpress Ctrl + X to EXITDELETING FILES/DIRECTORIES:$ rm year2005/docs/myfile.txt (deletes myfile.txt)$ rm song.txt book.txt readme.txt (deletes song.txt and readme.txt)$ rmdir year2006 (deletes the empty directory year2006)$ rm -r year2005 (deletes the non-empty directory year2005)CHANGING FILE PERMISSIONS:Users: a-all u-owner g-group o-othersPermissions: r-read w-write x-execute$ chmod a+x hello2 (gives all users execute permission for the file hello2)$ chmod go-w hwk1.txt (removes write permission from group and other users for the file hwk1.txt)$ chmod g+rw song.txt (gives read and write permissions to group users for the file song.txt) Kaynak: sct.emu.edu.tr belgesi-1156