mkfifo - make a FIFO special file (a named pipe)
int mkfifo ( const char *pathname, mode_t mode );
mkfifo makes a FIFO special file with name pathname. mode
specifies the FIFO's permissions. It is modified by the
process's umask in the usual way: the permissions of the
created file are (mode & ~umask).
A FIFO special file is similar to a pipe, except that it is
created in a different way. Instead of being an anonymous
communications channel, a FIFO special file is entered into
the file system by calling mkfifo.
Once you have created a FIFO special file in this way, any
process can open it for reading or writing, in the same way
as an ordinary file. However, it has to be open at both
ends simultaneously before you can proceed to do any input
or output operations on it. Opening a FIFO for reading nor-
mally blocks until some other process opens the same FIFO
for writing, and vice versa.
The normal, successful return value from mkfifo is 0. In
the case of an error, -1 is returned (in which case, errno
is set appropriately).
One of the directories in pathname did not allow search
pathname already exists.
Either the total length of pathname is greater than
PATH_MAX, or an individual file name component has a
length greater than NAME_MAX. In the GNU system, there
is no imposed limit on overall file name length, but
some file systems may place limits on the length of a
A directory component in pathname does not exist or is
a dangling symbolic link.
The directory or filesystem has no room for the new
A component used as a directory in pathname is not, in
fact, a directory.
pathname refers to a read-only filesystem.
mkfifo(1), read(2), write(2), close(2), stat(2), umask(2).