{
    "mode": "man",
    "parameter": "fifo",
    "section": "7",
    "url": "https://www.chedong.com/phpMan.php/man/fifo/7/json",
    "generated": "2026-10-04T14:11:24Z",
    "sections": {
        "NAME": {
            "content": "fifo - first-in first-out special file, named pipe\n",
            "subsections": []
        },
        "DESCRIPTION": {
            "content": "A  FIFO  special file (a named pipe) is similar to a pipe, except that it is accessed as part\nof the filesystem.  It can be opened by multiple processes  for  reading  or  writing.   When\nprocesses  are  exchanging  data  via the FIFO, the kernel passes all data internally without\nwriting it to the filesystem.  Thus, the FIFO special file has no contents on the filesystem;\nthe filesystem entry merely serves as a reference point so that processes can access the pipe\nusing a name in the filesystem.\n\nThe kernel maintains exactly one pipe object for each FIFO special file that is opened by  at\nleast  one  process.   The FIFO must be opened on both ends (reading and writing) before data\ncan be passed.  Normally, opening the FIFO blocks until the other end is opened also.\n\nA process can open a FIFO in nonblocking mode.  In this case, opening for read-only  succeeds\neven  if  no one has opened on the write side yet and opening for write-only fails with ENXIO\n(no such device or address) unless the other end has already been opened.\n\nUnder Linux, opening a FIFO for read and write will succeed both in blocking and  nonblocking\nmode.   POSIX  leaves  this  behavior undefined.  This can be used to open a FIFO for writing\nwhile there are no readers available.  A process that uses both ends of the connection in or‐\nder to communicate with itself should be very careful to avoid deadlocks.\n",
            "subsections": []
        },
        "NOTES": {
            "content": "For details of the semantics of I/O on FIFOs, see pipe(7).\n\nWhen a process tries to write to a FIFO that is not opened for read on the  other  side,  the\nprocess is sent a SIGPIPE signal.\n\nFIFO special files can be created by mkfifo(3), and are indicated by ls -l with the file type\n'p'.\n",
            "subsections": []
        },
        "SEE ALSO": {
            "content": "mkfifo(1), open(2), pipe(2), sigaction(2), signal(2), socketpair(2), mkfifo(3), pipe(7)\n\nLinux man-pages 6.7                          2023-10-31                                      fifo(7)",
            "subsections": []
        }
    },
    "summary": "fifo - first-in first-out special file, named pipe",
    "flags": [],
    "examples": [],
    "see_also": [
        {
            "name": "mkfifo",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/mkfifo/1/json"
        },
        {
            "name": "open",
            "section": "2",
            "url": "https://www.chedong.com/phpMan.php/man/open/2/json"
        },
        {
            "name": "pipe",
            "section": "2",
            "url": "https://www.chedong.com/phpMan.php/man/pipe/2/json"
        },
        {
            "name": "sigaction",
            "section": "2",
            "url": "https://www.chedong.com/phpMan.php/man/sigaction/2/json"
        },
        {
            "name": "signal",
            "section": "2",
            "url": "https://www.chedong.com/phpMan.php/man/signal/2/json"
        },
        {
            "name": "socketpair",
            "section": "2",
            "url": "https://www.chedong.com/phpMan.php/man/socketpair/2/json"
        },
        {
            "name": "mkfifo",
            "section": "3",
            "url": "https://www.chedong.com/phpMan.php/man/mkfifo/3/json"
        },
        {
            "name": "pipe",
            "section": "7",
            "url": "https://www.chedong.com/phpMan.php/man/pipe/7/json"
        }
    ]
}