man mkfifo (2): make a fifo file

Other Alias

mkfifoat

LIBRARY

Lb libc

SYNOPSIS

In sys/types.h In sys/stat.h Ft int Fn mkfifo const char *path mode_t mode Ft int Fn mkfifoat int fd const char *path mode_t mode

DESCRIPTION

The Fn mkfifo system call creates a new fifo file with name Fa path . The access permissions are specified by Fa 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 Fn mkfifoat system call is equivalent to Fn mkfifo except in the case where Fa path specifies a relative path. In this case the newly created FIFO is created relative to the directory associated with the file descriptor Fa fd instead of the current working directory. If Fn mkfifoat is passed the special value AT_FDCWD in the Fa fd parameter, the current working directory is used and the behavior is identical to a call to Fn mkfifo .

RETURN VALUES

Rv -std mkfifo

ERRORS

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

Bq Er ENOTSUP: The kernel has not been configured to support fifo's.
Bq Er ENOTDIR: A component of the path prefix is not a directory.
Bq Er ENAMETOOLONG: A component of a pathname exceeded 255 characters, or an entire path name exceeded 1023 characters.
Bq Er ENOENT: A component of the path prefix does not exist.
Bq Er 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.
Bq Er ELOOP: Too many symbolic links were encountered in translating the pathname.
Bq Er EROFS: The named file would reside on a read-only file system.
Bq Er EEXIST: The named file exists.
Bq Er EPERM: The parent directory of the named file has its immutable flag set, see the chflags(2) manual page for more information.
Bq Er 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.
Bq Er ENOSPC: There are no free inodes on the file system on which the fifo is being created.
Bq Er 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.
Bq Er EDQUOT: The user's quota of inodes on the file system on which the fifo is being created has been exhausted.
Bq Er EIO: An I/O error occurred while making the directory entry or allocating the inode.
Bq Er EIO: An I/O error occurred while reading from or writing to the file system.
Bq Er EFAULT: The Fa path argument points outside the process's allocated address space.

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

Bq Er EBADF: The Fa path argument does not specify an absolute path and the Fa fd argument is neither AT_FDCWD nor a valid file descriptor open for searching.
Bq Er ENOTDIR: The Fa path argument is not an absolute path and Fa fd is neither AT_FDCWD nor a file descriptor associated with a directory.

STANDARDS

The Fn mkfifo system call is expected to conform to St -p1003.1-90 . The Fn mkfifoat system call follows The Open Group Extended API Set 2 specification.

HISTORY

The Fn mkfifoat system call appeared in Fx 8.0 .