mknod -- make a special file node
Standard C Library (libc, -lc)
mknod(const char *path, mode_t mode, dev_t dev);
The file system node path is created with the file type and access permissions
specified in mode. The access permissions are modified by the
process's umask value.
If mode indicates a block or character special file, dev is a configuration
dependent specification denoting a particular device on the system.
Otherwise, dev is ignored.
The mknod() system call requires super-user privileges.
The mknod() function returns the value 0 if successful; otherwise the
value -1 is returned and the global variable errno is set to indicate the
The mknod() system call will fail and the file will be not created if:
[ENOTDIR] A component of the path prefix is not a directory.
[ENAMETOOLONG] A component of a pathname exceeded 255 characters, or
an entire path name exceeded 1023 characters.
[ENOENT] A component of the path prefix does not exist.
[EACCES] Search permission is denied for a component of the
[ELOOP] Too many symbolic links were encountered in translating
[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.
[EDQUOT] The directory in which the entry for the new node 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 node is being created has been exhausted.
[EROFS] The named file resides on a read-only file system.
[EEXIST] The named file exists.
[EFAULT] The path argument points outside the process's allocated
[EINVAL] Creating anything else than a block or character special
file (or a whiteout) is not supported.
chmod(2), mkfifo(2), stat(2), umask(2)
The mknod() function appeared in Version 6 AT&T UNIX.
FreeBSD 5.2.1 June 4, 1993 FreeBSD 5.2.1 [ Back ]