/ 
Unix-SavedIDs-0.3.0_00
River stage zero No dependents
/ Unix::SavedIDs

NAME

Unix::SavedIDs - interface to unix saved id commands: getresuid(), getresgid(), setresuid() and setresgid()

SYNOPSIS

    use Unix::SavedIDs;

	my($ruid,$euid,$suid) = getresuid();
	setresuid(10,10,10);

STATUS

This is alpha code. I'm going to be using it a lot in production and once I'm comfortable that it's working well I'll up the version number to 1.0 and call it a production release.

DESCRIPTION

This module is a simple interface to the c routines with the same names.

$<, $>, $(, $) and the POSIX setuid(),seteuid etc... functions give you access to the real uid/gid (ruid/rgid) and effective uid/gid (euid/egid), but there was no way to get or set the saved uid/gid (suid/sgid).

INTERFACE

getresuid()

returns a list of 3 elements, the current ruid, euid and suid or croaks on failure.

getresgid()

returns a list of 3 elements, the current rgid, egid and sgid or croaks on failure.

setresuid(ruid,euid,suid)

Sets the current ruid, euid and suid or croaks on failure.

Any arguments which are unset,undef or -1 tells setresuid to leave that value unchanged. E.G.

setresuid(500);
setresuid(500,undef,undef);
setresuid(500,-1,-1);

... all will set the ruid to 500 and leave the euid and suid alone and:

setresuid(undef,undef,500)

... will set your suid to 500 and leave your ruid and euid unchanged.

setresgid behaves in the same way.

setresgid(rgid,egid,sgid)

Sets the current rgid, egid and sgid or croaks on failure.

Please see setresuid() above to see how to leave an id unchanged.

TODO

  1. make more complete test suite

  2. make build system detect if saved ids are supported and do something clever if not

ACKNOWLEDGEMENTS

I recently discovered Proc::UID by Paul Fenwick. It does everything that this module does plus more. Sadly, its unmaintained since 2004 and the author specifically states that it is not for production code.

BUGS AND LIMITATIONS

It should do someting rational on systems without saved ids.

I only have Linux and OpenBSD systems to test on, so I have no idea how it might work on other operating systems. If you run a different OS, please let me know how this module works in your environment.

Please report any bugs or feature requests to bug-unix-savedids@rt.cpan.org, or through the web interface at http://rt.cpan.org.

AUTHOR

Dylan Martin <dmartin@cpan.org>

LICENSE AND COPYRIGHT

Copyright (c) 2008, Dylan Martin & Seattle Central Community College <dmartin@cpan.org>.

Permission to use, copy, modify, and distribute this software for any purpose with or without fee is hereby granted, provided that the above copyright notice and this permission notice appear in all copies.

DISCLAIMER

THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.