DragonFly On-Line Manual Pages

MKNOD(2)                 DragonFly System Calls Manual                MKNOD(2)

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 is S_IFIFO, mknod() and mknodat() are equivalent to mkfifo() and
     mkfifoat().  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 except when
     creating a new fifo.  See mkfifo(2) for more information.

     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.

     [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 DragonFly 2.7.

DragonFly 6.1-DEVELOPMENT        July 7, 2021        DragonFly 6.1-DEVELOPMENT