#!/opt/bin/perl
#
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#                                                                       #
#     Programm zur Ermittlung freier (unbenutzter) UID's und GID's      #
#                                                                       #
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#                                                                       #
#   Version 1.0     -   Written 02.04.95 by Steffen Beyer               #
#                                                                       #
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#                                                                       #
#   Copyright (C) 1995 by software design & management GmbH & Co. KG    #
#                                                                       #
#########################################################################
#
# Einige wichtige Defaulteinstellungen:
#
$version = 'Version 1.0';
#
$self = $0;
#
if ($self =~ /^.*\/([^\/]+)$/) { $self = $1; }
#
# Unterprogrammdefinitionen:
#
sub numerically { $a <=> $b }
#
# Aktuelle Passwort- und Gruppendatei einlesen (slurp):
#
setgrent;
#
while (($group,$passwd,$gid) = getgrent)
{
    if ($gid_group{$group} ne "")
    {
        die "Error: Group name '$group' is not unique!\n";
    }
    else { $gid_group{$group} = $gid; }
    if ($group_gid{$gid} ne "")
    {
        $group_gid{$gid} .= ", " . $group;
        warn "Warning: Group id '$gid' is not unique!\n";
    }
    else { $group_gid{$gid} = $group; }
}
#
endgrent;
#
setpwent;
#
while (($user,$passwd,$uid,$gid) = getpwent)
{
    if ($uid_user{$user} ne "")
    {
        die "Error: User name '$user' is not unique!\n";
    }
    else { $uid_user{$user} = $uid; }
    if ($user_uid{$uid} ne "")
    {
        $user_uid{$uid} .= ", " . $user;
        warn "Warning: User id '$uid' is not unique!\n";
    }
    else { $user_uid{$uid} = $user; }
    if ($group_gid{$gid} eq "")
    {
        warn "Warning: User '$user' belongs to non-existent group '$gid'!\n";
    }
#   $gid_user{$user} = $gid;
}
#
endpwent;
#
# Ausgabe der Ueberschrift:
#
printf("\n'%s' %s\n\n", $self, $version);
#
# Ausgabe der freien UID's:
#
printf("Free (unused) USER ID numbers:\n\n");
#
$previous = 0;
#
foreach $uid (sort numerically keys(%user_uid))
{
    if ($uid >= 0)
    {
        $difference = $uid - $previous;
        if ($difference == 1)
        {
            printf("%d ", $previous);
        }
        elsif ($difference == 2)
        {
            printf("%d %d ", $previous, $uid - 1);
        }
        elsif ($difference > 2)
        {
            printf("%d..%d ", $previous, $uid - 1);
        }
        else {}
        $previous = $uid + 1;
    }
}
#
printf("%d..*\n\n", $previous);
#
# Ausgabe der freien GID's:
#
printf("Free (unused) GROUP ID numbers:\n\n");
#
$previous = 0;
#
foreach $gid (sort numerically keys(%group_gid))
{
    if ($gid >= 0)
    {
        $difference = $gid - $previous;
        if ($difference == 1)
        {
            printf("%d ", $previous);
        }
        elsif ($difference == 2)
        {
            printf("%d %d ", $previous, $gid - 1);
        }
        elsif ($difference > 2)
        {
            printf("%d..%d ", $previous, $gid - 1);
        }
        else {}
        $previous = $gid + 1;
    }
}
#
printf("%d..*\n\n", $previous);
#
# Fertig.
#