HP-UX Reference (11i v3 07/02) - 2 System Calls (vol 5)

m
mknod(2) mknod(2)
NAME
mknod() - make a directory, special, or ordinary file
SYNOPSIS
#include <sys/stat.h>
int mknod(const char *path, mode_t mode, dev_t dev);
DESCRIPTION
The mknod() system call creates a new file named by the path name pointed to by path. The mode of the
new file is specified by the mode argument.
Symbolic constants that define the file type and file access permission bits are found in the
<sys/stat.h> header file and are used to construct the mode argument. The value of the mode argu-
ment should be the bit-wise inclusive OR of the values of the desired file type, miscellaneous mode bits, and
access permissions. See stat(5) for a description of the components of the file mode.
The owner ID of the file is set to the effective-user-ID of the process. If the set-group-ID bit of the parent
directory is set, the new file’s group ID is set to the group ID of the parent directory. Otherwise, the new
file’s group ID is set to the effective-group-ID of the process.
The file access permission bits of mode are modified by the process’s file mode creation mask: for each bit
set in the process’s file mode creation mask, the corresponding bit in the file’s mode is cleared (see
umask(2)).
In HFS file systems, the new file is created with three base access-control-list (ACL) entries, corresponding
to the file access permission bits (see acl(5)). On JFS file systems that support access control lists, when
creating a directory or regular file, optional ACL entries are created corresponding to the parent directory’s
default ACL entries (see aclv(5)). When creating a directory, the parent’s default ACL entries are also
copied as the new directory’s default ACL entries.
The dev argument is meaningful only if mode indicates a block or character special file, and is ignored oth-
erwise. It is an implementation- and configuration-dependent specification of a character or block I/O dev-
ice. The value of dev is created by using the
makedev() macro defined in
<sys/mknod.h>. The mak-
edev()
macro takes as arguments the major and minor device numbers, and returns a device
identification number which is of type dev_t. The value and interpretation of the major and minor device
numbers are implementation-dependent. For more information, see mknod(5) and the System Administra-
tion manuals for your system.
Only users having appropriate privileges can invoke
mknod() for file types other than FIFO files.
RETURN VALUE
mknod() returns the following values:
0 Successful completion.
-1 Failure. The new file is not created. errno
is set to indicate the error.
ERRORS
If
mknod() fails, errno is set to one of the following values.
[EACCES] The directory in which path would be created denies write permission, mode is for a
FIFO file and the caller does not have appropriate privileges.
[EACCES] A component of the path prefix denies search permission.
[EDQUOT] The user’s or group’s disk quota block or inode limit has been reached for this file sys-
tem.
[EEXIST] The named path already exists.
[EFAULT] The path argument points outside the process’s allocated address space. The reliable
detection of this error is implementation dependent.
[ELOOP] Too many symbolic links were encountered in translating the path name.
[ENAMETOOLONG]
The length of the specified path name exceeds PATH_MAX bytes, or the length of a
component of the path name exceeds NAME_MAX bytes while _POSIX_NO_TRUNC is
in effect.
192 Hewlett-Packard Company − 1 − HP-UX 11i Version 3: February 2007