FIFO special files

A FIFO special file sends data from one process to another so that the receiving process reads the data first-in-first-out (FIFO). A FIFO special file is also called a named pipe, or a FIFO. A FIFO special file can also be shared by a number of processes that were not created by forks. A FIFO special file can be written into and read by the same process using multiple threads.

FIFO special files can be shared between systems that use shared file systems. For more information about shared file systems, see Sharing file systems in a sysplex.

A program creates a FIFO special file with a mkfifo command or a mkfifo() function. The name is maintained in the file system until the named pipe is deleted by an rm command or an unlink() function.