NAME

       mkfifo, mkfifoat — make a fifo file

LIBRARY

       Standard C Library (libc, -lc)

SYNOPSIS

       #include <sys/types.h>
       #include <sys/stat.h>

       int
       mkfifo(const char *path, mode_t mode);

       int
       mkfifoat(int fd, const char *path, mode_t mode);

DESCRIPTION

       The mkfifo() system call creates a new fifo file with name path.  The access permissions are specified by
       mode and restricted by the umask(2) of the calling process.

       The fifo's owner ID is set to the process's effective user ID.  The fifo's group ID is set to that of the
       parent directory in which it is created.

       The  mkfifoat()  system call is equivalent to mkfifo() except in the case where path specifies a relative
       path.  In this case the newly created FIFO is created relative to the directory associated with the  file
       descriptor  fd  instead  of  the  current  working  directory.  If mkfifoat() is passed the special value
       AT_FDCWD in the fd parameter, the current working directory is used and the behavior is  identical  to  a
       call to mkfifo().

RETURN VALUES

       The  mkfifo()  function  returns  the  value  0 if successful; otherwise the value -1 is returned and the
       global variable errno is set to indicate the error.

ERRORS

       The mkfifo() system call will fail and no fifo will be created if:

       [ENOTSUP]          The kernel has not been configured to support fifo's.

       [ENOTDIR]          A component of the path prefix is not a directory.

       [ENAMETOOLONG]     A component of a pathname exceeded 255 characters, or an  entire  path  name  exceeded
                          1023 characters.

       [ENOENT]           A component of the path prefix does not exist.

       [EACCES]           A component of the path prefix denies search permission, or write permission is denied
                          on the parent directory of the fifo to be created.

       [ELOOP]            Too many symbolic links were encountered in translating the pathname.

       [EROFS]            The named file would reside on a read-only file system.

       [EEXIST]           The named file exists.

       [EPERM]            The  parent directory of the named file has its immutable flag set, see the chflags(2)
                          manual page for more information.

       [ENOSPC]           The directory in which the entry for the new fifo is being placed cannot  be  extended
                          because there is no space left on the file system containing the directory.

       [ENOSPC]           There are no free inodes on the file system on which the fifo is being created.

       [EDQUOT]           The  directory  in which the entry for the new fifo is being placed cannot be extended
                          because the user's quota of disk blocks on the file system  containing  the  directory
                          has been exhausted.

       [EDQUOT]           The  user's  quota of inodes on the file system on which the fifo is being created has
                          been exhausted.

       [EIO]              An I/O error occurred while making the directory entry or allocating the inode.

       [EINTEGRITY]       Corrupted data was detected while reading from the file system.

       [EFAULT]           The path argument points outside the process's allocated address space.

       In addition to the errors returned by the mkfifo(), the mkfifoat() may fail if:

       [EBADF]            The path argument does not specify an absolute path and the  fd  argument  is  neither
                          AT_FDCWD nor a valid file descriptor open for searching.

       [ENOTDIR]          The  path  argument  is  not  an  absolute  path and fd is neither AT_FDCWD nor a file
                          descriptor associated with a directory.

SEE ALSO

       chflags(2), chmod(2), mknod(2), stat(2), umask(2)

STANDARDS

       The mkfifo() system call is expected to conform  to  ISO/IEC  9945-1:1990  (“POSIX.1”).   The  mkfifoat()
       system call follows The Open Group Extended API Set 2 specification.

HISTORY

       The mkfifoat() system call appeared in FreeBSD 8.0.

Debian                                           March 30, 2020                                        MKFIFO(2)