Question

What kind of files or nodes /dev/ directory contains and how do I access or see device files?

Answer 1

Block Device Files:­ Block device files talks to devices block by block [1 block at a time (1 block = 512 bytes to 32KB)]. Examples: – USB disk, CDROM, Hard Disk # ls /dev/sd* brw­rw—­ 1 root root 8, 0 Mar 15 2009 sda brw­rw—­ 1 root root 8, 1 Mar 15 2009 sda1 brw­rw—­ 1 root root 8, 2 Mar 15 2009 sda2 brw­rw—­ 1 root root 8, 3 Mar 15 2009 sda3 brw­rw—­ 1 root root 8, 4 Mar 15 2009 sda4 brw­rw—­ 1 root root 8, 16 Mar 15 2009 sdb Character Device Files:­ Character device files talk to devices character by character. Examples: – Virtual terminals, terminals, serial modems, random numbers #ls /dev/tty* crw­rw—­ 1 root root 4, 64 Mar 15 2009 ttyS0 crw­rw—­ 1 root root 4, 65 Mar 15 2009 ttyS1 crw­rw—­ 1 root root 4, 66 Mar 15 2009 ttyS2 crw­rw—­ 1 root root 4, 67 Mar 15 2009 ttyS3