NAME

     mknod - create a directory or special or ordinary file


SYNOPSIS

     #include <sys/types.h>
     #include <sys/stat.h>
     #include <fcntl.h>
     #include <unistd.h>

     int mknod(const char *pathname, mode_t mode, dev_t dev


DESCRIPTION

     mknod attempts to create a  filesystem  node  (file,  device
     special  file  or  named  pipe) named pathname, specified by
     mode and dev.

     mode specifies both the permissions to use and the  type  of
     node to be created.

     It should be a combination (using bitwise OR) of one of  the
     file  types  listed  below  and  the permissions for the new
     node.

     The permissions are modified by the process's umask  in  the
     usual  way:  the permissions of the created node are (mode &
     ~umask).

     The file type should be one of S_IFREG, S_IFCHR, S_IFBLK and
     to  specify  a  normal  file  (which will be created empty),
     character special file, block special file  or  FIFO  (named
     pipe),  respectively,  or  zero,  which will create a normal
     file.

     If the file type is S_IFCHR or S_IFBLK  then  dev  specifies
     the major and minor numbers of the newly created device spe-
     cial file; otherwise it is ignored.

     The newly created node will be owned by the effective uid of
     the  process.   If the directory containing the node has the
     set group id bit set, or if the filesystem is  mounted  with
     BSD  group  semantics,  the  new node will inherit the group
     ownership from its parent directory; otherwise  it  will  be
     owned by the effective gid of the process.


RETURN VALUE

     mknod returns zero on success, or -1 if  an  error  occurred
     (in which case, errno is set appropriately).


ERRORS

     EPERM
          mode requested creation of something other than a  FIFO
          (named pipe), and the caller is not the superuser; also
          returned if the filesystem containing pathname does not
          support the type of node requested.

     EINVAL
          mode requested creation of something other than a  nor-
          mal file, device special file or FIFO.

     EEXIST
          pathname already exists.

     EFAULT
          pathname points outside your accessible address space.

     EACCES
          The parent directory does not allow write permission to
          the  process, or one of the directories in pathname did
          not allow search (execute) permission.

     ENAMETOOLONG
          pathname was too long.

     ENOENT
          A directory component in pathname does not exist or  is
          a dangling symbolic link.

     ENOTDIR
          A component used as a directory in pathname is not,  in
          fact, a directory.

     ENOMEM
          Insufficient kernel memory was available.

     EROFS
          pathname refers to a file on a read-only filesystem.

     ELOOP
          Too many symbolic links were encountered  in  resolving
          pathname.

     ENOSPC
          The device containing pathname has no room for the  new
          node.


CONFORMING TO

     SVr4 (but the call requires privilege and  is  thus  not  in
     POSIX),  4.4BSD.   The  Linux  version differs from the SVr4
     version in that it  does  not  require  root  permission  to
     create  pipes,  also in that no EMULTIHOP, ENOLINK, or EINTR
     error is documented.


BUGS

     The mknod call cannot  be  used  to  create  directories  or
     socket  files,  and cannot be used to create normal files by
     users other than the superuser.

     There are many infelicities in the protocol underlying  NFS.
     Some of these affect mknod.


SEE ALSO

     read(2), write(2), fcntl(2), unlink(2),  open(2),  mkdir(2),
     mount(2), socket(2), fopen(3).