NAME

mknod − make a directory, or a special or ordinary file

SYNOPSIS

int mknod (path, mode, dev)
char ∗path;
int mode, dev;

DESCRIPTION

mknod creates a new file named by the path name pointed to by path. The mode of the new file is initialized from mode. Where the value of mode is interpreted as follows:

0170000 file type; one of the following: 0010000 fifo special
0020000 character special
0040000 directory
0060000 block special
0100000 or 0000000 ordinary file
0004000 set user ID on execution
00020#0 set group ID on execution if # is 7, 5, 3, or 1
            enable mandatory file/record locking if # is 6, 4, 2, or 0
0001000 save text image after execution
0000777 access permissions; constructed from the following: 0000400 read by owner
0000200 write by owner
0000100 execute (search on directory) by owner
0000070 read, write, execute (search) by group
0000007 read, write, execute (search) by others

The owner ID of the file is set to the effective user ID of the process.  The group ID of the file is set to the effective group ID of the process. 

Values of mode other than those above are undefined and should not be used.  The low-order 9 bits of mode are modified by the process’s file mode creation mask: all bits set in the process’s file mode creation mask are cleared [see umask(2)]. If mode indicates a block or character special file, dev is a configuration-dependent specification of a character or block I/O device.  If mode does not indicate a block special or character special device, dev is ignored. 

mknod may be invoked only by the super-user for file types other than FIFO special. 

mknod fails and the new file is not created if one or more of the following are true:

­[EPERM] The effective user ID of the process is not super-user. 

­[ENOTDIR] A component of the path prefix is not a directory. 

­[ENOENT] A component of the path prefix does not exist. 

­[EROFS] The directory in which the file is to be created is located on a read-only file system. 

­[EEXIST] The named file exists. 

­[EFAULT] path points outside the allocated address space of the process. 

­[ENOSPC] No space is available. 

­[EINTR] A signal was caught during the mknod system call. 

­[ENOLINK] path points to a remote machine and the link to that machine is no longer active. 

­[EMULTIHOP] Components of path require hopping to multiple remote machines. 

SEE ALSO

chmod(2), exec(2), mkdir(1), umask(2), fs(4). 

DIAGNOSTICS

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

WARNING

If mknod is used to create a device in a remote directory (Remote File Sharing), the major and minor device numbers are interpreted by the server. 

September 02, 1992