linux commands

mkdir

mkdir is make directory .

• mkdir [option] directory_name(s)

mkdir customer
# with permission flag
mkdir -m 777 customer
# create directory inside parent
mkdir -p company/customer

touch

make a empty file with touch command

touch file1

cd

cd means change directory .

• cd [option] [directory]

• option
• -P
• -L

# current directory
cd .
# parents of current directory
cd ..
# home directory
cd ~
# change directory with forwars slash
cd /usr/sbin

pwd

pwd is present work directory

clear

clear command removes all previous commands.

head

head commands display few lines from first of file

tail

tail commands display few lines from last of file

less

lessdisplay all content of file without scrolling

cp

cp command is copy

• cp [options] name new_name
• cp <option> from to(with rename)

cp file1 /home/john/file1

mv

mv = move

mv [options] source target

mv file3 dir1/file3

rmdir

remove empty directories .

• rmdir [option] directory_names

rmdir dir1 dir2
# parents
rmdir -p dir1/dir/dir

rm

remove commands use for delete files and directory.

• rm [options] [-r directories] filenames

rm file1
#recursively
rm -r file1
#force
rm -f file1
#recursively force
rm -rf file1

search

find

locate

locate is faster , database system.

• install locate

sudo apt-get update
sudo apt-get install mlocate
sudo updatedb

• locate [options] name(s)

locate desired_file

users

• who <option>

# currently log in user
who
#log in user
whoami

every user has unique user id (uid) that is greather than 1000.