mknod(2) SYSTEM CALLS 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
The file access permissions are specified in mode by the
0007777 bits, and may be constructed by an OR of the follow-
ing 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 effec-
tive 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.
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mknod(2) SYSTEM CALLS 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.
See makedev(3C).
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 com-
ponent 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
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mknod(2) SYSTEM CALLS mknod(2)
system call.
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. Other-
wise, 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 inter-
preted by the server.
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