MKFIFO(1) BSD Reference Manual MKFIFO(1)
mkfifo - make FIFOs
mkfifo [-m mode] 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 mode Set the file permission bits of newly created directories 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 or >0 if an error occurred.
mkdir(1), rm(1), mkfifo(2), mknod(8)
The mkfifo utility is expected to be IEEE Std 1003.2-1992 ("POSIX.2") compliant.
The mkfifo command appeared in 4.4BSD. MirBSD #10-current September 4, 2020 1