MKNOD(2) BSD Programmer's Manual MKNOD(2)
mknod - make a special file node
#include <sys/stat.h> int mknod(const char *path, mode_t mode, dev_t dev);
The device special file path is created with the major and minor device numbers extracted from mode. The access permissions of path are descen- dant from the umask(2) of the parent process. If mode indicates a block or character special file, dev is a configura- tion dependent specification of a character or block I/O device and the superblock of the device. If mode does not indicate a block special or character special device, dev is ignored. mknod() requires superuser privileges.
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 will be not created if: [ENOTDIR] A component of the path prefix is not a directory. [ENAMETOOLONG] A component of a pathname exceeded {NAME_MAX} characters, or an entire path name exceeded {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. [EPERM] The process's effective user ID is not superuser. [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 filesystem 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 filesystem containing the directory has been exhausted. [EDQUOT] The user's quota of inodes on the filesystem on which the node is being created has been exhausted. [EROFS] The named file resides on a read-only filesystem. [EEXIST] The named file exists. [EFAULT] path points outside the process's allocated address space. [EINVAL] The process is running within an alternate root directory, as created by chroot(2). This value is only returned if the currently running kernel has the following option set: option HARD_CHROOT
chmod(2), chroot(2), stat(2), umask(2)
A mknod() function call appeared in Version 6 AT&T UNIX. MirBSD #10-current June 4, 1993 1