=encoding utf8
=head1 NAME
POSIX::1003::User - POSIX handling user and groups
=head1 SYNOPSIS
use POSIX::1003::User;
=head1 DESCRIPTION
=head1 FUNCTIONS
=head2 Standard POSIX
User and group management is provided via many functions, which are
not portable either in implementation or in availability.
See also L<http://www.cs.berkeley.edu/~daw/papers/setuid-usenix02.pdf>
=head3 Get/set users
The implementation of L<setuid()|POSIX::1003::User/"Get/set users"> differs per platform. L<seteuid()|POSIX::1003::User/"Get/set users">
is more consistent and widely available. L<setresuid()|POSIX::1003::User/"Get/set users"> is the most
powerful, but not everywhere. Functions which are not implemented
will return error ENOSYS.
B<. Example>
my $uid = getuid();
defined $uid or die $!;
setuid($uid)
or die "cannot set uid to $uid: $!\n";
my ($ruid, $euid, $suid) = getresuid;
defined $ruid or die $!;
setresuid($ruid, $euid, $suid)
or die $!;
=over 4
=item B<geteuid>()
=item B<getresuid>()
=item B<getuid>()
=item B<seteuid>($euid)
=item B<setresuid>($ruid, $euid, $suid)
example:
# see also the set*uid examples above
my @mygroups = getgroups();
@mygroups or die $!;
setgroups(1,2,3) or die $!;
=item B<setreuid>($ruid, $euid)
=item B<setuid>($uid)
=back
=head3 Get/set groups
The same use and limitations as the uid functions.
=over 4
=item B<getegid>()
=item B<getgid>()
=item B<getgroups>()
Returns a list of group-ids, which may (or may not) contain the effective
group-id.
=item B<getresgid>()
=item B<setegid>($egid)
=item B<setgid>($gid)
=item B<setregid>($rgid, $egid)
=item B<setresgid>($rgid, $egid, $sgid)
=back
=head3 Information about users
=over 4
=item B<getlogin>()
The username associated with the controling terminal.
Simply L<perlfunc/getlogin>
=item B<getpwent>()
Simply L<perlfunc/getpwent>
=item B<getpwnam>($username)
Simply L<perlfunc/getpwnam>
=item B<getpwuid>($userid)
Simply L<perlfunc/getpwuid>
example:
my ($name, $passwd, $uid, $gid, $quota, $comment,
$gcos, $dir, $shell, $expire) = getpwuid($uid);
my $uid = getpwnam($username);
my $name = getpwuid($userid);
=back
=head3 Information about groups
=over 4
=item B<getgrent>()
Simply L<perlfunc/getgrent>
=item B<getgrgid>($groupid)
Simply L<perlfunc/getgrgid>
=item B<getgrnam>($groupname)
Simply L<perlfunc/getgrnam>
=back
=head1 SEE ALSO
This module is part of POSIX-1003 distribution version 1.02,
built on November 10, 2020. Website: F<http://perl.overmeer.net/CPAN>. The code is based on L<POSIX>, which
is released with Perl itself. See also L<POSIX::Util> for
additional functionality.
=head1 COPYRIGHTS
Copyrights 2011-2020 on the perl code and the related documentation
by [Mark Overmeer]. For other contributors see ChangeLog.
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
See F<http://dev.perl.org/licenses/>