Driver sr needs updating debian
Two standard types of device files exist; unfortunately their names are, for historical reasons, rather counter-intuitive, and explanations of the difference between the two are often incorrect as a result.
Character special files or character devices provide unbuffered, direct access to the hardware device.
In Linux, to get a character device for a disk one must use the "raw" driver, though one can get the same effect as opening a character device by opening the block device with the Linux-specific flag.
There are also special files in MS-DOS, OS/2, and Microsoft Windows.The Free BSD and Dragon Fly BSD implementations have named the virtual device file system , but there are many variants.Darwin, and operating systems such as mac OS based on it, have a purely kernel-based device file system.An application attempting to access a device already in use would discover itself unable to open the device file node.A variety of device driver semantics are implemented in Unix and Linux concerning concurrent access. The assignment of these numbers occurs uniquely in different operating systems and on different computer platforms.