Basic Bash commands for LINUX.

• man  - format and display the on-line manual pages

              man  <commandName>

              ex: man grep, man cal

           

• mkdir - make directories

              mkdir  <directoryName>

              ex: mkdir xyz

• cd  - change directory

             cd  <directoryName>

             ex: cd xyz      

• ls   - list directory contents

              ls  -[option] <diraname>

              ex: ls home

• touch  - creates a file

              touch <fileName>

              ex: touch file.txt , touch file.eps touch file

• vi -(editor) opens a file and if it doesn't exist, creates a file

              vi  <fileName>

              ex: vi file.txt , vi file.c , vi file.tcl , vi file.sh

• gedit - (editor) (same as vi)

• cp - copy file and directory

               cp -[options] <source> <destination>

               ex: cp file1 file2, 

• rm - remove files or directories

               rm [option] <fileName>

               ex: rm file1.txt 

• cut  - remove sections from each line of files

              cut [option] <fileName>

              ex: cut -c2 file.txt                //remove second character from file file.txt

• paste  - merge lines of files

             paste [option] <fileName>
            ex: paste file1                      //without options works like "cat" command
                  paste -s file 1                   //join all lines in file1

• cat - concatenate files and print on the standard output

              cat [option] <fileName>

              ex: cat  file.txt  , cat file1.txt file2.txt              

• su - run a shell with substitute user and group IDs

             su [option] [user]

             ex: su root , su  - <username>

• sudo , sudoedit - execute a command as another user

              //reboot your system in 20 minutes

              sudo shutdown -r +20  "rebooting to fix network issue" 

• time - time a simple command or give resource usage

                time [options] command [arguments]

                ex: /usr/bin/time ls 

• date  - print or set the system date and time

            date [option] [+format]

            date [-u|--utc|--universal] [MMDDhhmm[[CC]YY][.ss]]
           ex: date , date  +%T

• cal - displays a calendar

           cal [-smjy13] [[month] year]

           ex: cal , cal -3 ,cal -yy

• pwd - print name of current/working directory

           pwd [option]

          ex: pwd

• chpasswrd - update passwords in batch mode

         chpasswd [options]  

         ex: chpasswd

• grep
• sed
• tail
• head
• free
• top
• ps
• locate
• find
• sort
• pipe '|'
• kill
• bkill
• shutdown
• poweroff
• exit
• USER
• chmod
• chown
• links
• ln
• wget
• email
• mount/unmount
• gunzip/gzip
• tar
• route
• netstate
• alias/unalias
• lastlog
• service
• iconfig
• display
• usermod
• make
• arp
• ping
• watch
• basename
• dirname
• at
• dos2unix
• du
• timeconfig
• script
• tac
• more
• dmsg
• convert