MKNOD(2)

NAME
mknod, mkfifo - make a special file

SYNOPSIS
#include <sys/types.h>
#include <unistd.h>
#include <sys/stat.h>
int mknod(const char *path, mode_t mode, dev_t dev)
int mkfifo(const char *path, mode_t mode)

DESCRIPTION
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)

RETURN VALUE
Upon successful completion a value of 0 is returned. Otherwise, a value of -1 is returned and errno is set to indicate the error.

ERRORS
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 prefix.

[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.

SEE ALSO
chmod(2), stat(2), umask(2).