Device

source

How Linux Works

Device files as device I/O interface

not all devices have device files

e.g., network interfaces, should be like character devices, but due to the difficulty using file interfaces, the kernel offers other I/O interfaces

Block device

file type: b

program access data from a block device in fixed chunks

total size is fixed -> easy to split and index

disk device is a type of block device

Character device

file type: c

work with data streams: read/write data with character device

don’t have size

example: printer

Pipe device

file type: p

like character device, but with another process ar the end of I/O stream instead of a kernel driver

Socket device

file type: s

used for interprocess communication, usually outside of /dev directory

sysfs device path