1MKNOD(2)                   Linux Programmer's Manual                  MKNOD(2)
2
3
4

NAME

6       mknod, mknodat - create a special or ordinary file
7

SYNOPSIS

9       #include <sys/stat.h>
10
11       int mknod(const char *pathname, mode_t mode, dev_t dev);
12
13       #include <fcntl.h>           /* Definition of AT_* constants */
14       #include <sys/stat.h>
15
16       int mknodat(int dirfd, const char *pathname, mode_t mode, dev_t dev);
17
18   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
19
20       mknod():
21           _XOPEN_SOURCE >= 500
22               || /* Since glibc 2.19: */ _DEFAULT_SOURCE
23               || /* Glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
24

DESCRIPTION

26       The system call mknod() creates a filesystem node (file, device special
27       file, or named pipe) named pathname, with attributes specified by  mode
28       and dev.
29
30       The  mode  argument specifies both the file mode to use and the type of
31       node to be created.  It should be a combination (using bitwise  OR)  of
32       one  of  the  file types listed below and zero or more of the file mode
33       bits listed in inode(7).
34
35       The file mode is modified by the process's umask in the usual  way:  in
36       the  absence  of a default ACL, the permissions of the created node are
37       (mode & ~umask).
38
39       The file type must be one of S_IFREG,  S_IFCHR,  S_IFBLK,  S_IFIFO,  or
40       S_IFSOCK to specify a regular file (which will be created empty), char‐
41       acter special file, block special file, FIFO (named pipe), or UNIX  do‐
42       main  socket,  respectively.   (Zero  file  type  is equivalent to type
43       S_IFREG.)
44
45       If the file type is S_IFCHR or S_IFBLK, then dev  specifies  the  major
46       and  minor numbers of the newly created device special file (makedev(3)
47       may be useful to build the value for dev); otherwise it is ignored.
48
49       If pathname already exists, or is a symbolic link, this call fails with
50       an EEXIST error.
51
52       The  newly  created  node will be owned by the effective user ID of the
53       process.  If the directory containing the node has the set-group-ID bit
54       set,  or if the filesystem is mounted with BSD group semantics, the new
55       node will inherit the group ownership from its parent directory; other‐
56       wise it will be owned by the effective group ID of the process.
57
58   mknodat()
59       The  mknodat() system call operates in exactly the same way as mknod(),
60       except for the differences described here.
61
62       If the pathname given in pathname is relative, then it  is  interpreted
63       relative  to  the  directory  referred  to by the file descriptor dirfd
64       (rather than relative to the current working directory of  the  calling
65       process, as is done by mknod() for a relative pathname).
66
67       If  pathname  is relative and dirfd is the special value AT_FDCWD, then