Basic Linux Command

 

Ø File Handling Linux Commands

# man command (show all information about this command) 

# pwd (print [current] working directory)

# cd (change [current working] directory)

# cd (return to your original directory)

# ls (list directory)

# ls -a (show all directory include hidden directory)

# ls -l (show all directory with property like size, ownership etc.)

# ls -al (show all directory include hidden directory with property like size, ownership etc.)

# mkdir d (Create new directory d)

# rmdir d (Remove directory d)

# rm f1 [f2...] (Remove file(s) f1...)

# rm -rf d1 [d2...] (Recursively remove all files in the directories)

# mv f1 [f2...] d (Move file f to directory d)

# mv d1 d2 (Rename directory d1 as d2)

# cp source-file(s) destination (copy file one directory to another)

# cp f1 f2 (Copy file f1, and name it as f2)

# cp -r d1 d2 (Recursively copy a directory d1, and name it as d2)

# ln -s realFileName linkName (Create a symbolic link to realFileName and name it as linkName)

# chmod mode f (Change protection mode of f)

# less f (Show file contents of a text file f)

# cat > hello.txt (Create file and input from keybord)

# history (print recently used commands)

  

Ø Check the Linux Version, Release name & Kernel version

# uname -a (Print all Information)

# uname -r (Print the kernel name)

# cat /p

# roc/version

# cat /etc/issue

# cat /etc/redhat-release

# lsb_release –a

# tail /etc/redhat-release

Ø Check Swap Space

# swapon –summary (summary of swap space)

# cat /proc/swaps (swap usage information)

# free -h (display use and free swap space in gigabyte)

# top (use to check swap space)

  

Ø Linux System Administrator

   

# uptime (show system running time and currently logged users)

# uptime -v (check uptime version)

# w (shows who is logged into your system and what they are currently doing)

# users (show who are currently logged in to your system)

# who (return user name, date, time and host information)

# who -b (Displays last system reboot date and time)

# who -r (Shows current runlet)

# who -a (Displays all information in cumulatively)

#  crontab -l (List schedule jobs for current user)

# service httpd start(execute the script)

# top (displays processor activity of your system and also displays tasks managed)

# last (display terminal, time, date, system reboot or boot)

# ps -ef | grep init (show init process only)

# kill- 9 7508(Process ID) (kill command to terminate process)

# reboot (restart the system)

# init 6 (restart the system)

Ø File System

# cat output.log | less or more (view file)

# whoami (Prints the username of the user that you are currently logged in)

# locate text.txt (Find files on your system by name)

# sort file.txt (Sorting lines of files in ascending order)

# sort -r file.txt (Sorting lines of text files in descending order)

# vi /etc/test.txt (text editor)

# free (Free command shows free, total and swap memory information in bytes)

# free -h (Free command shows free, total and swap memory information in gigabyte)

# grep test /etc/passwd (grep search for a given string in a file)

# grep -i serachstring /etc/passwd (grep search for a given string in a file)

# find / -name test (used to search files, strings and directories)

# lsof -u erpdev (List of all open files by user erpdev)

Ø Archival

# tar -cvf archive-name.tar /home (tar command is used to compress files and folders)

# tar -xvf archive-name.tar (extract tar archive file)

# zip original.zip original (zip original file)

# unzip original.zip ( unzip original.zip file)

Ø Network

# ssh -v (check the version of ssh user)

# ssh remote_host (you connect to a remote host)

# scp (Copy files securely and remotely over servers)

# ftp 192.168.50.2 (used to connect to remote ftp host)

# sftp 192.168.50.2 (sftp is secure file transfer protocol)

# ftp > mput *.txt (Putting multiple files in remote host)

# ftp > mget *.txt (mget to download multiple files from remote host)