Unix::Mknod(3pm)

NAME
Unix::Mknod - Perl extension for mknod, major, minor, and makedev

SYNOPSIS
 use Unix::Mknod qw(:all);
 use File::stat;
 use Fcntl qw(:mode);

 $st=stat('/dev/null');
 $major=major($st->rdev);
 $minor=minor($st->rdev);

 mknod('/tmp/special', S_IFCHR|0600, makedev($major,$minor+1));

DESCRIPTION
This module allows access to the device routines major()/minor()/makedev() that may or may not be macros in .h files.

It also allows access to the mknod(2) system call.

FUNCTIONS

mknod($filename, $mode, $rdev)
    Creates a block or character device special file named $filename. Must be run as a privileged user, usually root. Returns 0 on success and -1 on failure, like "POSIX::mkfifo" does.

$major = major($rdev)
    Returns the major number for the device special file as defined by the st_rdev field from the stat(3) call.

$minor = minor($rdev)
    Returns the minor number for the device special file as defined by the st_rdev field from the stat(3) call.

$rdev = makedev($major, $minor)
    Returns the st_rdev number for the device special file from the $major and $minor numbers.

NOTES
There are 2 other perl modules that implement the mknod(2) system call, but they have problems working on some platforms. "Sys::Mknod" does not work on AIX because it uses the syscall(2) generic system call which AIX does not have. "Mknod" implements S_IFIFO, which on most platforms is not implemented in mknod(1), but rather mkfifo(1) (which is implemented in POSIX perl module).

The perl module "File::Stat::Bits" also implements major() and minor() (and a version of makedev() called dev_join). They are done as a program to get the bit masks at compile time, but if major() and minor() are implemented as sub routines, the argument could be something as simple as an index to a lookup table (and thereby having no decernable relation to its result).

BUGS
Running "make test" as non root will not truly test the functions, as in most UNIX like OSes, mknod(2) needs to be invoked by a privelaged user, usually root.

SEE ALSO
$ERRNO or $! for the specific error message.

File::Stat::Bits, Mknod, POSIX, Sys::Mknod

major(9), minor(9), mkfifo(1), mknod(8)

AUTHOR
Jim Pirzyk, <pirzyk@freebsd.org>

COPYRIGHT AND LICENSE
Copyright (c) 2005-2023 University of Illinois Board of Trustees All rights reserved.

Developed by: Campus Information Technologies and Educational Services,
              University of Illinois at Urbana-Champaign

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the ``Software''), to deal with the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

* Redistributions of source code must retain the above copyright
  notice, this list of conditions and the following disclaimers.

* Redistributions in binary form must reproduce the above copyright
  notice, this list of conditions and the following disclaimers in the
  documentation and/or other materials provided with the distribution.

* Neither the names of Campus Information Technologies and Educational
  Services, University of Illinois at Urbana-Champaign, nor the names
  of its contributors may be used to endorse or promote products derived
  from this Software without specific prior written permission.

THE SOFTWARE IS PROVIDED ``AS IS'', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE CONTRIBUTORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS WITH THE SOFTWARE.