Golgappa.net | Golgappa.org | BagIndia.net | BodyIndia.Com | CabIndia.net | CarsBikes.net | CarsBikes.org | CashIndia.net | ConsumerIndia.net | CookingIndia.net | DataIndia.net | DealIndia.net | EmailIndia.net | FirstTablet.com | FirstTourist.com | ForsaleIndia.net | IndiaBody.Com | IndiaCab.net | IndiaCash.net | IndiaModel.net | KidForum.net | OfficeIndia.net | PaysIndia.com | RestaurantIndia.net | RestaurantsIndia.net | SaleForum.net | SellForum.net | SoldIndia.com | StarIndia.net | TomatoCab.com | TomatoCabs.com | TownIndia.com
Interested to Buy Any Domain ? << Click Here >> for more details...


what is block device and character device?



what is block device and character device?..

Answer / guest

$ ls -altr /dev/
brw-rw---- 1 root disk 8, 6 2010-07-26 14:20
sda6 --> block device
crw-rw---- 1 root root 10, 59 2010-07-26 14:21 device-
mapper --> character device
Answer :

Character devices deal with IO on a character by character
basis. The most obvious example is a keyboard, where every
key generates a character on the device. The mouse is
another. Every motion or button click sends a character to
the /dev/input/mouse0 device. To test it out do
$cat /dev/input/mouse0 , then move your mouse (see what
happens)

Block devices read data in larger chunks or blocks. Data
storage devices, such as IDE hard drives (/dev/hd), SCSI
hard drives (/dev/sd), and CD-ROMs (/dev/cdrom or /dev/sr0)
are block devices. IO interactions with block devices
transact with chunks of data (blocks), which allows large
quantities of data to be moved back and forth more
efficiently(unlike character device). eg: $df -h

Generically, block devices can be mounted and are cached,
and char devices are for communication devices, aren’t
cached nor block aligned, and can’t be mounted.

Specifically, /dev/scd* (block) are for cdroms, providing
the block access and commands for ejecting, closing,
playing, etc.

The corresponding character device for the cdrom is /dev/sg1

Is This Answer Correct ?    2 Yes 0 No

Post New Answer

More Linux General Interview Questions

What is the full form of linux and unix?

0 Answers  


How do you check the status of all the services?

0 Answers  


Is linux os free?

0 Answers  


What is a shell script?

0 Answers  


Your default umask is 002. What does this mean?

0 Answers  


How do I stop a linux script from command line?

0 Answers  


How do you go to a directory in linux?

0 Answers  


What is semaphore explain with example?

0 Answers  


What is the maximum length for a filename under linux?

0 Answers  


What is yum in linux?

0 Answers  


What is the difference between an argument and an option (or switch)?

0 Answers  


How to see the list of mounted devices on linux?

0 Answers  


Categories