mknod, mkfifo - make a special file
int mknod(const char *path, mode_t mode, dev_t dev)
int mkfifo(const char *path, mode_t mode)
Mknod creates a new file whose name is path. The mode of the new file
(including special file bits) is initialized from mode, as defined in
<sys/stat.h>. (The protection part of the mode is modified by the
process's mode mask (see umask(2))). The first block pointer of the i-
node is initialized from dev and is used to specify which device the
special file refers to.
If mode indicates a block or character special file, dev is the device
number of a character or block I/O device. The low eight bits of the
device number hold the minor device number that selects a device among
the devices governed by the same driver. The driver is selected by the
major device number, the next eight bits of the device number.
If mode does not indicate a block special or character special device,
dev is ignored. (For example, when creating a ``fifo'' special file.)
Mknod may be invoked only by the super-user, unless it is being used to
create a fifo.
The call mkfifo(path, mode) is equivalent to
mknod(path, (mode & 0777) | S_IFIFO, 0)
Upon successful completion a value of 0 is returned. Otherwise, a value
of -1 is returned and errno is set to indicate the error.
Mknod will fail and the file mode will be unchanged if:
[ENOTDIR] A component of the path prefix is not a directory.
[ENAMETOOLONG] The path name exceeds PATH_MAX characters.
[ENOENT] A component of the path prefix does not exist.
[EACCES] Search permission is denied for a component of the path
[ELOOP] Too many symbolic links were encountered in translating
the pathname. (Minix-vmd)
[EPERM] The process's effective user ID is not super-user.
[EIO] An I/O error occurred while making the directory entry or
allocating the inode.
[ENOSPC] The directory in which the entry for the new node 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
node is being created.
[EROFS] The named file resides on a read-only file system.
[EEXIST] The named file exists.
[EFAULT] Path points outside the process's allocated address space.
chmod(2), stat(2), umask(2).