mknod(2) mknod(2)
NAME
mknod - make a directory, or a special or ordinary file
SYNOPSIS
#include <sys/types.h>
#include <sys/stat.h>
int mknod(const char *path, modet mode, devt dev);
DESCRIPTION
mknod creates a new file named by the path name pointed to by path.
The file type and permissions of the new file are initialized from
mode.
The file type is specified in mode by the SIFMT bits, which must be
set to one of the following values:
SIFIFO fifo special
SIFCHR character special
SIFDIR directory
SIFBLK block special
SIFREG ordinary file
SINSEM semaphore
SINSHD shared data
The file access permissions are specified in mode by the 0007777
bits, and may be constructed by an OR of the following values:
SISUID 04000 Set user ID on execution.
SISGID 020#0 Set group ID on execution if # is 7, 5, 3, or 1
Enable mandatory file/record locking if # is 6, 4, 2, or 0
SISVTX 01000 Save text image after execution.
SIRWXU 00700 Read, write, execute by owner.
SIRUSR 00400 Read by owner.
SIWUSR 00200 Write by owner.
SIXUSR 00100 Execute (search if a directory) by owner.
SIRWXG 00070 Read, write, execute by group.
SIRGRP 00040 Read by group.
SIWGRP 00020 Write by group.
SIXGRP 00010 Execute by group.
SIRWXO 00007 Read, write, execute (search) by others.
SIROTH 00004 Read by others.
SIWOTH 00002 Write by others
SIXOTH 00001 Execute by others.
The owner ID of the file is set to the effective user ID of the
process. The group ID of the file is set to the effective group ID
of the process. However, if the SISGID bit is set in the parent
directory, then the group ID of the file is inherited from the
parent. If the group ID of the new file does not match the effective
group ID or one of the supplementary group IDs, the SISGID bit is
cleared.
7/91 Page 1
mknod(2) mknod(2)
The access permission bits of mode are modified by the process's file
mode creation mask: all bits set in the process's file mode creation
mask are cleared [see umask(2)]. If mode indicates a block or
character special file, dev is a configuration-dependent
specification of a character or block I/O device. If mode does not
indicate a block special or character special device, dev is ignored.
mknod may be invoked only by a privileged user for file types other
than FIFO special.
If path is a symbolic link, it is not followed.
mknod fails and creates no new file if one or more of the following
are true:
EEXIST The named file exists.
EINVAL dev is invalid.
EFAULT path points outside the allocated address space
of the process.
ELOOP Too many symbolic links were encountered in
translating path.
EMULTIHOP Components of path require hopping to multiple
remote machines and the file system type does not
allow it.
ENAMETOOLONG The length of the path argument exceeds
{PATHMAX}, or the length of a path component
exceeds {NAMEMAX} while POSIXNOTRUNC is in
effect.
ENOTDIR A component of the path prefix is not a
directory.
ENOENT A component of the path prefix does not exist or
is a null pathname.
EPERM The effective user ID of the process is not
super-user.
EROFS The directory in which the file is to be created
is located on a read-only file system.
ENOSPC No space is available.
EINTR A signal was caught during the mknod system call.
Page 2 7/91
mknod(2) mknod(2)
ENOLINK path points to a remote machine and the link to
that machine is no longer active.
SEE ALSO
chmod(2), exec(2), umask(2), makedev(3C), mkfifo(3C), fs(4), stat(5).
mkdir(1) in the User's Reference Manual.
DIAGNOSTICS
Upon successful completion a value of 0 is returned. Otherwise, a
value of -1 is returned and errno is set to indicate the error.
NOTES
If mknod creates a device in a remote directory using Remote File
Sharing, the major and minor device numbers are interpreted by the
server.
7/91 Page 3