Hello Readers..here are some basic commands that we use in Linux

 1. File Handling :

•     mkdir- make directories

     Usage: mkdir[OPTION]DIRECTORY...
     Example: mkdir rahul
     

•      ls- list directory contents

     Usage: ls[OPTION]...[FILE]...
     Example: ls,ls-1,ls rahul
     

•      cd-changes directories

     Usage: cd[DIRECTORY] 
     Example: cd rahul

•   pwd- print name of current working directory

     Usage:pwd
 

•  vim-Vi Improved,a programmers text editor

     Usage: vim[OPTION] [file]...
     Example: vim file1.txt

•   cp-copy files and directories

     Usage: cp[OPTION]..SOURCE DEST
     Example:cp sample.txt sample_copy.txt
             cp sample_copy.txt target_dir

• mv-move(rename)files

     Usage: mv[OPTION]..SOURCE DEST
     Example: mv source.txt target_dir
             mv previous.txt new.txt

• rm-remove files or directories

     Usage: rm[OPTION] [path] [pattern]
     Example: rm file.txt
   

• find-search for files in a directory hierarchy

     Usage: find[OPTION] [path] [pattern]
     Example: find file1.txt

• history-prints recently used commands

     Usage: history

 2. Text Processing:

•     cat-concatenate files and print on the standard output

    Usage: cat[OPTION][FILE]...
    Example: cat file1.txt

•     echo-display a line of text

    Usage: find[OPTION] [string]...
    Example: echo hello
            echo $HOME 

 3. System Administration:

•     chmod- change file access permission

    Usage: chmod [OPTION] [MODE] [FILE]
    Example: chmod 744 math.sh
    

•     chown: change file owner and group

    Usage: chmod [OPTION]...OWNER[:GROUP][MODE][FILE]
    Example: chmod remo math.txt

•     su: change user ID

    Usage: su[OPTION][LOGIN]
    Example: su math

•     passwd:update a user's authentication tokens

    Usage: passwd[OPTION]
    Example: passwd
    

•  who: show who is logged on

    Usage: who[OPTION]
    Example: who,who -b

 4. Process Management:

• ps:report a  snapshort of the current processes

    Usage: ps[OPTION]
    Example: ps,ps -el
    

• kill: to kill a process

    Usage: kill[OPTION] pid
    Example: kill -9 2275

 5. Archival:

•      tar: to archive a file

    Usage: tar[OPTION]DEST SOURCE
    Example: cvf/home/archive.tar/home/origial

• zip: package and compress (archive) files

    Usage: zip[OPTION]DEST SOURCE
    Example: zip original.zip original
 

• unzip: test,list and extract compressed files in a ZIP archive

    Usage: unzip filename
    Example: unzip original.zip

 6. Network:

• 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 [OPTION] [user]@hostname

    Example: ssh-X guest@10.105.11.20

• scp: secure copy

        "scp copies files between hosts on a network"
    Usage: scp[options] [[user]@host1:file1] [[user]@host2:file2]

    Example: scp file1.txt guest@10.105.11.20:~/Desktop/

 7. File Systems:

• fdisk-partition manipulator

    Example: sudo fdisk -1
    

• mount: mount a file system

    Usage: mount -t type device dir
    Example: mount/dev/sda5/media/target

• unmount: unmount file systems

    Usage: unmount[OPTIONS]dir |device..
    Example: unmount/media/target

• du: estimate file space usage

    Usage: du[OPTION]..[FILE]
    Example: du

• df: report filesystem disk space usage

    Usage: df[OPTIONS]..[FILE]..
    Example: df

• quota: display disk usage and limits

    Usage: quota [OPTION]
    Example: quota -v