| mkfifo | [ -mmode]
      fifo_name ... | 
mkfifo creates the fifos requested, in the order
  specified, using mode 0666 modified by the current
  umask(2).
The options are as follows:
  - -m
- Set the file permission bits of newly-created fifos to
      mode. The mode is specified as in
      chmod(1). In symbolic mode
      strings, the “+” and “-” operators are
      interpreted relative to an assumed initial mode of
    “a=rw”
mkfifo requires write permission in the
    parent directory.
The mkfifo utility exits 0 on success,
  and >0 if an error occurs.
The mkfifo utility is expected to be
  IEEE Std 1003.2-1992 (“POSIX.2”)
  compliant.
mkfifo command appeared in
  4.4BSD.