4:null

From Linux Man Pages

      null, zero - data sink
      

Contents 1 DESCRIPTION 2 NOTES 3 FILES 4 RELATED 5 CATEGORY

DESCRIPTION

      Data written on a null or zero special file is discarded.
 
      Reads  from the null special file always return end of file, whereas reads from zero always return \0 characters.
 
      null and zero are typically created by:
 
             mknod -m 666 /dev/null c 1 3
             mknod -m 666 /dev/zero c 1 5
             chown root:root /dev/null /dev/zero

NOTES

      If these devices are not writable and readable for all users, many programs will act strangely.

FILES

      /dev/null
      /dev/zero

RELATED

      chown(1), mknod(1), full(4)

CATEGORY