Master Essential Linux Commands: ls, cd, mkdir, rm, cp, mv, and More

Command Prompt

The prompt root@localhost ~# shows the current user ( root), hostname ( localhost) and the present working directory ( ~ = home). A trailing # indicates a super‑user prompt; a regular user sees $.

Command Syntax

General form: command [options] [arguments]. Square brackets denote optional parts.

Listing Directory Contents – ls

Common options: -a: show all files, including hidden ones. -l: long listing with detailed information. -d: display directory attributes instead of its contents. -h: human‑readable file sizes. -i: show inode numbers.

[root@localhost ~]# ls
anaconda-ks.cfg  test
[root@localhost ~]# ls -a
. .. anaconda-ks.cfg .bash_history .bash_logout .bash_profile .bashrc .cache .config .cshrc .tcshrc test
[root@localhost ~]# ls -l
total 4
-rw-------. 1 root root 2752 Nov 10 02:51 anaconda-ks.cfg
drwxr-xr-x. 2 root root 6 Nov 12 19:26 test
[root@localhost ~]# ls -lh
total 4.0K
-rw-------. 1 root root 2.7K Nov 10 02:51 anaconda-ks.cfg
drwxr-xr-x. 2 root root 6 Nov 12 19:26 test
[root@localhost ~]# ls -i
71259104 anaconda-ks.cfg 36099565 test

File‑permission strings consist of ten characters. The first character indicates the file type ( - regular file, d directory, l symbolic link). The next nine characters are three groups of rwx for owner, group and others. Example: -rw------- means a regular file readable and writable only by the owner; drwxr-xr-x grants full access to the owner and read/execute to group and others. A trailing dot ( .) signals ACL information; the number after it is the link count.

Directory Management Commands

Create Directory – mkdir

[root@localhost ~]# mkdir otherFolder
[root@localhost ~]# ls
anaconda-ks.cfg  otherFolder  test
[root@localhost ~]# mkdir folder_2/test_2
mkdir: cannot create directory "folder_2/test_2": No such file or directory
[root@localhost ~]# mkdir -p folder_2/test_2
[root@localhost ~]# ls
anaconda-ks.cfg  folder_2  otherFolder  test
[root@localhost ~]# ls folder_2/
test_2

Without -p, mkdir cannot create nested directories; -p enables recursive creation.

Change Directory – cd

[root@localhost ~]# cd /folder_2/test_2
[root@localhost test_2]# cd
[root@localhost ~]# cd -
/root/folder_2/test_2
[root@localhost test_2]# cd ../../otherFolder
[root@localhost otherFolder]# cd ..
[root@localhost ~]

cd ~

– go to the current user’s home directory. cd - – return to the previous directory. cd .. – move up one level. cd (no arguments) – go to the home directory.

Absolute paths start with /; relative paths are resolved from the current directory.

Print Working Directory – pwd

[root@localhost ~]# pwd
/root

Displays the full path of the current directory.

Remove Empty Directory – rmdir

[root@localhost ~]# rmdir otherFolder
[root@localhost ~]# ls
anaconda-ks.cfg  folder_2  test
[root@localhost ~]# rmdir folder_2
rmdir: failed to remove "folder_2": Directory not empty

rmdir

succeeds only on empty directories.

Remove Files or Directories – rm

Typical usage:

rm -rf [file_or_directory]

-r

: recursive removal (files and sub‑directories). -f: force removal without prompts.

[root@localhost ~]# rm abc.txt
rm: remove regular empty file "abc.txt"? y
[root@localhost ~]# rm test
rm: cannot remove "test": Is a directory
[root@localhost ~]# rm -r test
rm: remove directory "test"? y
[root@localhost ~]# rm -rf folder_2

Copy Files – cp

Syntax:

cp [options] source target

-r

: copy directories recursively. -p: preserve mode, ownership and timestamps. -d: preserve links. -a: archive mode (equivalent to -rpd).

[root@localhost ~]# cp bbc.txt folder_a
[root@localhost ~]# cp folder_a folder_b
cp: omitting directory "folder_a"
[root@localhost ~]# cp -r folder_a folder_b
[root@localhost ~]# ls folder_b
folder_a  test_1
[root@localhost ~]# cp -a bbc.txt folder_b

Without -p or -a, the copy’s modification time may differ from the source. Using -a or -p retains the original timestamps.

Move or Rename – mv

[root@localhost ~]# mv bbc.txt abc.txt
[root@localhost ~]# ls
abc.txt  anaconda-ks.cfg
[root@localhost ~]# mkdir test
[root@localhost ~]# mv abc.txt test/
[root@localhost ~]# ls test/
abc.txt

If source and destination are in the same directory, mv acts as a rename; otherwise it moves the file.

Link Files – ln

Hard link (shares the same inode):

[root@localhost ~]# touch bbb.txt
[root@localhost ~]# ln bbb.txt folder/ccc.txt

Hard links cannot cross filesystem boundaries and cannot be created for directories.

Symbolic (soft) link:

[root@localhost ~]# ln -s bbb.txt folder_b/eee.txt

Soft links store the pathname of the target and have their own inode. If the target is removed, the link becomes dangling.

Common Top‑Level Directories

/

– root directory. /bin – essential user commands. /sbin – system administration commands (root only). /boot – boot loader files. /dev – device files. /etc – configuration files. /home – regular user home directories. /lib – shared libraries. /mnt – temporary mount points. /media – removable media mount points. /root – super‑user home directory. /tmp – temporary files. /proc – kernel and process information (virtual filesystem). /sys – device and driver information (virtual filesystem). /usr – user utilities and applications. /var – variable data such as logs and databases.