Originální popis anglicky:
mknod - create a special or ordinary file
Návod, kniha: Linux Programmer's Manual
#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);
The system call
mknod creates a filesystem node (file, device special
file or named pipe) named
pathname, with attributes specified by
mode and
dev.
The
mode argument 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 must be one of
S_IFREG,
S_IFCHR,
S_IFBLK,
S_IFIFO or
S_IFSOCK to specify a normal file (which will be
created empty), character special file, block special file, FIFO (named pipe),
or Unix domain socket, respectively. (Zero file type is equivalent to type
S_IFREG.)
If the file type is
S_IFCHR or
S_IFBLK then
dev specifies
the major and minor numbers of the newly created device special file;
otherwise it is ignored.
If
pathname already exists, or is a symbolic link, this call fails with
an EEXIST error.
The newly created node will be owned by the effective user ID 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 group ID of the process.
mknod returns zero on success, or -1 if an error occurred (in which case,
errno is set appropriately).
- EACCES
- The parent directory does not allow write permission to the
process, or one of the directories in the path prefix of pathname
did not allow search permission. (See also
path_resolution(2).)
- EEXIST
- pathname already exists.
- EFAULT
- pathname points outside your accessible address
space.
- EINVAL
- mode requested creation of something other than a
normal file, device special file, FIFO or socket.
- ELOOP
- Too many symbolic links were encountered in resolving
pathname.
- ENAMETOOLONG
- pathname was too long.
- ENOENT
- A directory component in pathname does not exist or
is a dangling symbolic link.
- ENOMEM
- Insufficient kernel memory was available.
- ENOSPC
- The device containing pathname has no room for the
new node.
- ENOTDIR
- A component used as a directory in pathname is not,
in fact, a directory.
- EPERM
- mode requested creation of something other than a
regular file, FIFO (named pipe), or Unix domain socket, and the caller is
not privileged (Linux: does not have the CAP_MKNOD capability);
also returned if the filesystem containing pathname does not
support the type of node requested.
- EROFS
- pathname refers to a file on a read-only
filesystem.
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.
POSIX 1003.1-2001 says: "The only portable use of
mknod() is to
create a FIFO-special file. If
mode is not S_IFIFO or
dev is not
0, the behavior of
mknod() is unspecified."
Under Linux, this call cannot be used to create directories. One should make
directories with
mkdir, and FIFOs with
mkfifo.
There are many infelicities in the protocol underlying NFS. Some of these affect
mknod.
fcntl(2),
mkdir(2),
mount(2),
path_resolution(2),
socket(2),
stat(2),
umask(2),
unlink(2),
mkfifo(3)
