can you tell me something about char devices in linux

[abhikohokade]

can you tell me something about char devices in linux and how to write a program to access this devices in our program

[hazel]

can you tell me something about char devices in linux and how to write a program to access this devices in our program

character devices are simply devices that the kernel reads from or writes to one character at a time (as distinct from block devices like disks that are read from or written to in blocks). Char devices include consoles, sound devices, ports, etc. Each is characterised by a unique pair of numbers called the major and minor device nodes.
If you do a full listing (ls -l) of the dev directory, you will see that the first character of the listing for each device is 'c' for char or 'b' for block.
You may find a char subdirectory in /dev. This lists all your char devices by their device nodes with links to the actual names.

[abhikohokade]

i want to write device driver for that char device
do u have any idea about this.

e.g
I want to access usb file system in my c program using kernel module.

[atreyu]

That would be a block device (e.g. /dev/sdb1), not a char device.