NAME

       mknod, mknodat — make a special file node

LIBRARY

       Standard C Library (libc, -lc)

SYNOPSIS

       #include <sys/stat.h>

       int
       mknod(const char *path, mode_t mode, dev_t dev);

       int
       mknodat(int fd, const char *path, mode_t mode, dev_t dev);

DESCRIPTION

       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  mknodat()  system  call  is equivalent to mknod() except in the case where path specifies a relative
       path.  In this case the newly created device node is created relative to the  directory  associated  with
       the  file  descriptor  fd  instead  of the current working directory.  If mknodat() is passed the special
       value AT_FDCWD in the fd parameter, the current working directory is used and the behavior  is  identical
       to a call to mknod().

RETURN VALUES

       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 error.

ERRORS

       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 path prefix.

       [ELOOP]            Too many symbolic links were encountered in translating the pathname.

       [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.

       [EINTEGRITY]       Corrupted data was detected while reading from the file system.

       [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 address space.

       [EINVAL]           Creating anything else than a block or character special file (or a whiteout)  is  not
                          supported.

       In addition to the errors returned by the mknod(), the mknodat() may fail if:

       [EBADF]            The  path  argument  does  not specify an absolute path and the fd argument is neither
                          AT_FDCWD nor a valid file descriptor open for searching.

       [ENOTDIR]          The path argument is not an absolute path and  fd  is  neither  AT_FDCWD  nor  a  file
                          descriptor associated with a directory.

SEE ALSO

       chmod(2), mkfifo(2), stat(2), umask(2)

STANDARDS

       The mknodat() system call follows The Open Group Extended API Set 2 specification.

HISTORY

       The mknod() function appeared in Version 4 AT&T UNIX.  The mknodat() system call appeared in FreeBSD 8.0.

Debian                                           March 30, 2020                                         MKNOD(2)