How to open a KDE file manager

To open a KDE file manager


       $ konqueror --profile filemanagement

How to open a Gnome File Manager

To open a Gnome file manager

        $ nautilus

How to see the last fifteen lines of the files one ,two and three

To see last fifteen lines of the files one,two and three

        $ tail -15 one two three

How to locate commands

To locate commands

        $ which firefox

How to add an iso image in repository

To add an iso image in repository,first you must mount the iso image then go to(generally requires root privileges)


    $ nano /etc/apt/sources.list    

then write this command :
   
    deb file:/media/iso/ lenny main contrib

How to mount an ISO image

Make a location to mount an ISO image
      
          $ mkdir /media/iso

To mount an iso image (generally requires root privileges).

         $ mount -t iso9660 -o loop filename.iso /media/iso
         

How to print the number of characters, words, and lines

To print the number of lines,characters and  words  in the specified files.


        $ wc filename

How to print a message to each user

To print a message to each user except those who've disabled message reception.


         $ wall

          Type Ctrl-D to end the message.

How to Print the current system users

To print the current system users.

         $ w

How to print the system uptime

To print the system uptime.

       $ uptime

How to Unmount the specified filesystem

To unmount the specified file system (generally it requires root privileges).

       $ umount device

How to print a network path to the host

Uses echo requests to determine and print a network path to the host.

        $ traceroute host

How to print the display of system processes

To print a display of system processes that's continually updated until the user presses the q key.

           $ top

How to Open a login session on the specified host

To open a login session on the specified host.


        $ telnet host

How to launche a program that allows a chat-like

To launch a program that allows a chat-like dialog with the specified user.

        $ talk user

How to complete all pending input/output operations

To complete all pending input/output operations (it requires root privileges).

          $ sync

How to disables use of the specified device for swapping

To disable use of the specified device for swapping (it requires root privileges).


       $ swapoff device

How to use of the specified device for swapping

To enable use of the specified device for swapping (it requires root privileges).


        $ swapon device

How to pause the command interpreter to pause

To cause the command interpreter to pause for the specified number of seconds.


        $ sleep time

How to Shutdown the system after a number of minutes

To shutdown the system after the specified number of minutes elapses (requires root privileges). The -r option causes the system to be rebooted once it has shut down.

       $ shutdown minutes
       $ shutdown -r minutes

How to reset the terminal status

To clear the terminal screen and resets the terminal status.

       $ reset

How to Display the processes associated with the current userid

To display the processes associated with the current user id or displays a description of each process.


          $ ps
        $ ps -Aux

How to change the current user's password

To change the current user's password, or that of the specified user (requires root privileges). The command prompts for the new password.


            $ passwd
          $ passwd user

How to create a Linux swap space on the hard disk

To create a Linux swap space on the specified hard disk partition (requires root privileges).

       $ mkswap device

How to cancel printing of the specified print queue entries

To cancel printing of the specified print queue entries. Use lpq to determine the contents of the print queue.

       $ lprm job

How to print the specified files

To Print the specified files
   
        $ lpr files

How to print the entries of the print queue

To print the entries of the print queue.
 

       $ lpq

How to locate files with names containing the specified pattern

To locate files with names containing the specified pattern.

    $ locate pattern

How to Check the spelling of the contents of the file

To check the spelling of the content of the specified files.

    $ ispell files

How to display all background jobs

To Display all background jobs.

    $ jobs

How to load a module dynamically

Dynamically loads the specified module .It requires root privileges

    $ insmod module

How to launch the GNU Text info help system

 To launch the GNU Text info help system


        $ info

How to launch the GNU Texinfo help system

How to display the name of the host

To display or sets the name of the host


    $ hostname
    $ hostname name

How to print the first several lines of the file

To print the first several lines of each specified file.

    $ head filename

Make a pdf of a manual page

make a pdf of a manual page

~$ man -t man | ps2pdf - > man.pdf

How to expand the specified files

To expand the specified files. Generally, a compressed file has the same name as the original file, followed by  . gz


         $ gunzip filename

How to compress the specified files

To compress the specified files,generally a compressed file has the same name as the original file, followed by . gz

          $ gzip files

How to format the media inserted in the specified drive

To format the media inserted in the specified floppy disk drive. The command performs a low-level format only. it does not create a filesystem. To create a filesystem, issue the mkfs command after formatting the media.

    $ fdformat device

How to search the specified files for text matching

To search the specified files for text matching the specified pattern  and print matching lines. The -i option specifies that matching is performed without regard to case. The -n option specifies that each line of output is preceded by the file name and line number. The -v option reverses the matching, causing non-matched lines to be printed.





    $ grep pattern files
    $ grep -i pattern files
    $ grep -n pattern files
    $ grep -v pattern files

How to open a FTP connection to the specified host

To open a FTP connection to the specified host


  $ ftp hostname

How to display the amount of used and free system memory

To display the amount of used and free system memory
   
    $ free

How to print descriptions of the specified users

To print descriptions of the specified users.
   
    $ finger users

How to search the specified path for files with specified pattern

To search the specified path for files with names matching the specified pattern (usually enclosed in single quotes) and prints their names.

    $ find path  -name pattern  -print

How to run a jar file ?

 To run a jar file

$ java -jar filename.jar

Brings the current jobs to the foreground.

To bring the current job (or the specified jobs) to the foreground.

    $ fg
    $ fg job

How to compare two files ?

To compare two files, reporting all discrepancies.


$ cmp file1 file2

How to compare two files ?

To compares two files, reporting all discrepancies. Similar to the cmp command, though the output format differs.



$ diff file1 file2

How to place the current job in the background ?

 To place the current job (or, by using the alternative form, the specified jobs) in the background, suspending its execution so that a new user prompt appears immediately. Use the jobs command to discover the identities of background jobs.



    $ bg
    $ bg jobs

How to cancel the execution of a job scheduled ?

To cancel the  execution of a job scheduled via the 'at' command. Use the atq command to discover the identities of scheduled jobs.


$ atrm job

Which are the jobs pending ?

Prints descriptions of jobs pending via the 'at' command.


$ atq

How to search the manual pages of the specified keyword?

To search the manual pages for occurrences of the specified keyword and prints short descriptions from the beginning of matching manual pages.


$ apropos keyword

Some MS-DOS commands & related linux commands

How to find the disk space used by the current directory

To print the amount of the disk space used by the current directory

~$ du /directory

How to find free disk space in each mounted filesystem

To print the amount of free disk space in each mounted file system

~$ df

how to clear the content in CDRW

To clear a CDRW

~$ cdrecord -v dev=/dev/cdrom blank=fast                          

how to mount a cdrom image

To mount a cdrom image (read only)

 ~$ mount -o loop cdrom.iso /mnt/dir

To know the information of a host name or ip address

To get the information of a hostname whois


~$ whois google.com

How to lists wireless networks in range

 To lists the wireless networks in range

 ~$ iwlist scan

How to set ethernet interface speed manually

To set manually ethernet interface speed

~$ ethtool -- change eth0 autoneg off speed 100 duplex full

How to solve screen resolution problem in Debian

To solve screen resolution problem in Debian. First you have to find the possible resolutions with  xrandr -q

$ xrandr -q

Screen 0: minimum 320 x 200, current 1024 x 768, maximum 1024 x 1024
VGA connected 1024x768+0+0 (normal left inverted right x axis y axis) 270mm x 200mm
1024x768 60.0*
800x600 85.1 75.0
640x480 85.0 85.0 75.0 59.9
720x400 70.1

Now you can set your resolution with command
 $ xrandr -s 1024x768

More Details
 $man xrandr