NAME
mkfifo
, mkfifoat
— make a FIFO file
SYNOPSIS
#include
<sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
int
mkfifo
(const
char *path, mode_t
mode);
int
mkfifoat
(int
fd, const char
*path, mode_t
mode);
DESCRIPTION
mkfifo
()
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
()
function is equivalent to mkfifo
() except that where
path specifies a relative path, the newly created FIFO
is created relative to the directory associated with file descriptor
fd instead of the current working directory.
If
mkfifoat
()
is passed the special value AT_FDCWD
(defined in
<fcntl.h>
) in the
fd parameter, the current working directory is used
and the behavior is identical to a call to
mkfifo
().
RETURN VALUES
A 0 return value indicates success. A -1 return value indicates an error, and an error code is stored in errno.
ERRORS
mkfifo
() and
mkfifoat
() will fail and no FIFO will be created
if:
- [
EOPNOTSUPP
] - The kernel has not been configured to support FIFOs.
- [
ENOTDIR
] - A component of the path prefix is not a directory.
- [
ENAMETOOLONG
] - A component of a pathname exceeded
{NAME_MAX}
characters, or an entire path name exceeded{PATH_MAX}
characters. - [
ENOENT
] - A component of the path prefix does not exist.
- [
EACCES
] - Search permission is denied for a component of the path prefix.
- [
ELOOP
] - Too many symbolic links were encountered in translating the pathname.
- [
EROFS
] - The named file resides on a read-only file system.
- [
EEXIST
] - The named file exists.
- [
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.
- [
EIO
] - An I/O error occurred while reading from or writing to the file system.
- [
EFAULT
] - path points outside the process's allocated address space.
Additionally, mkfifoat
() will 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 reading.
SEE ALSO
STANDARDS
The mkfifo
and
mkfifoat
functions conform to IEEE
Std 1003.1-2008 (“POSIX.1”).
HISTORY
The mkfifoat
function appeared in
OpenBSD 5.0.