HP 3000 Manuals HP 3000 Manuals
mknod
Make a FIFO special file.
Makes a directory, or a special or regular file.
Syntax
#include <sys/stat.h>
int mknod(const char *path, mode_t mode, dev_t dev);
Parameters
path The pathname of a file.
mode Specifies the file type and file access permission.
dev Specifies the major and minor device numbers.
Return Values
0 Successful completion
-1 Error and errno is set to indicate the error.
Description
mknod() 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 defining 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 argument 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)).
The new file is created with three base access-control-list (ACL)
entries, corresponding to the file access permission bits.
The dev argument is meaningful only if mode indicates a block
or character special file, and is ignored otherwise. It is an
implementation- and configuration-dependent specification of a character
or block I/O device. The value of dev is created by using the makedev()
macro defined in <sys/mknod.h>. The makedev() 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 Administration manuals for your
system.
Only users with appropriate privileges can invoke mknod for file types
other than FIFO files.
Implementation Considerations
Proper discretion should be used when using mkrnod to create generic
device files in an HP Clustered Environment. A generic device file
accessed from different cnodes in a cluster applies to different physical
devices. Thus the file's ownership and permissions might not be
appropriate in the context of every individual cnode in the cluster.
Errors
If an error occurs, errno is set to one of the following values:
EACCES CAUSE One of the following:
* 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.
* A component of the path prefix denies search
permission.
ACTION One of the following:
* Make sure that the calling process has search
permission to all components of t he pathname.
* Make sure that the calling process has execute
permission to the file.
EEXIST CAUSE The named path already exists.
ACTION Make sure that path specifies a directory that does
not already exist.
EFAULT CAUSE The path argument points outside the process's
allocated address space. The reliable detection of
this error is implementation dependent.
ACTION Make sure that the pointer is correctly initialized.
ELOOP CAUSE Too many symbolic links were encountered in
translating the path name.
ACTION Make sure that there is not a loop in the symbolic
links that loops more than POSIX_SYMLOOP.
ENAMETOOLONG CAUSE 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.
ACTION Make sure that both the component's length and the
full pathname length do not exceed the {NAME_MAX} or
{PATH_MAX} limits.
ENOENT CAUSE Either of the following:
* The path argument is null.
* A component of the path prefix does not exist.
ACTION Specify a valid pathname.
Table 4-0. (cont.)
ENOSPC CAUSE Not enough space on the file system.
ACTION Extend accounting limits for the directory in which
the file is located, or fr ee up disk space.
ENOTDIR CAUSE A component of the path prefix is not a directory.
ACTION Specify a valid pathname.
EPERM CAUSE The effective-user-ID of the process does not match
that of the super-user, and the file type is not FIFO
special.
ACTION Refer to the kill() function description for signal
permission rules.
EROFS CAUSE The directory in which the file is to be created is
located on a read-only file system.
ACTION Create the slink on a writable volume (file system).
See Also
mknod(1M), chmod(2), exec(2), mkdir(2), setacl(2), umask(2), cdf(4),
fs(4), acl(5), mknod(5), stat(5), types(5).