In Unix (and Unix-like) operating systems, /dev/null is a character device file which discards all data written to it, and gives End of File (EOF) for all reads. Because it is located in the /dev, or device, directory, it is commonly known as the 'null device.' Synonyms include the 'black hole' and the 'bit bucket.' The null device is part of the standard Unix directory structure
It is commonly used to prevent the output of programs from appearing on the screen (usually when they are run in scripts). It has oft been used in jokes and puns. For instance, the original BSD Daemon, drawn by Phil Foglio, featured a demon standing near a 'bit bucket.' Another usage would be on an Internet forum or IRC, when someone says something to the effect "Flames will be redirected to /dev/null."
- "The Linux System Administrator's Guide, Chapter 5" (Retrieved 2007-04-15).