Request for feature: adduser --alias

[Raul Miller <rdm@test.legislate.com>]

I'm picking up maintenance of sash, and I'd like to make its postinst offer
to create a root alias account "sashroot", and only offer to change the
root shell as a fallback.

The problem is that adduser doesn't support the functionality I need,
and I don't think it's appropriate to be playing around with raw passwd
file locking in a postinst.

What do other people think?

-- 
Raul

P.S. here's what I'm thinking of for the postinst:

#!/usr/bin/perl
#
# rewritten to favor creation of sashroot over modification of root

$passwd="*";
$home= "/root";
$gid= 0;
$count= 0;
$gcos= '';
$rootshell= '/bin/sh';

sub ask {
	my ($prompt)= @_;
	$prompt =~/\[(.*?)\]\s*$/;
	my @options= split '/', $1;
	while (1) {
		print $prompt;
		my $input= lc substr <>, 0, -1;
		for (@options) {
			return $input if $input eq lc $_;
			return lc $_ if $input eq '' && ! /^[a-z]*$/;
		}
		my @opts= map {"`\U$_'"} @options;
		print "Please answer ".(join ', ', @opts[0..$#opts-1])." or $opts[$#opts].\n";
	}
}

while (@ent= getpwent) {
    my ($Name, $Passwd, $Uid, $Gid, $Quota, $Comment, $Gcos, $Dir, $Shell)= @ent;
    next if $Uid;
    if ('/bin/sash' eq $Shell) {
	if ($Passwd =~/[*]/) {
            if ($Passwd eq '*LK*') {		# explicitly ignore these entries
	        exit if $name eq "sashroot";    # presume this is intentional
                next;
            }
            exec "/bin/passwd $Name";		# clean up after premature exit
        }
        exit;                                   # presume this is intentional
    }
    $rootshell= $Shell if $Name eq 'root';      # in case we decide to change it
    ($name, $passwd, $uid, $gid, $quota, $comment, $gcos, $dir, $shell)= @ent
        if $Passwd !~/[*]/;                     # remember for later
    warn "sashroot already exists, but shell is not /bin/sash\n"
        if "sashroot" eq $Name;
    $count++;
}

print "The best way to use sash is to install it as a superuser login shell.\n";
if (0 == $count) {
    print "Currently, there is no root login shell!\n"
} elsif (1 == $count) {
    print "Currently, ${name}'s login shell is set to $shell.\n"
} else {
    print "Currently, there are $count superuser shells.  For example,\n";
    print "${name}'s login shell is set to $shell.\n";
}

if ('y' eq ask "Shall I make a sashroot account with sash as its login shell? [Y/n] ") {
     print "Creating sashroot account for superuser\n";
     exec "adduser --alias --home '$home' --uid 0 --gid '$gid' sashroot";
     die "can't add sashroot alias";
}

if ('y' eq ask "Shall I make sash the login shell for root? [y/N] ") {
    open ROOTSHELL, ">/var/lib/sash/rootshell" or die "can't register root shell";
    print ROOTSHELL "$rootshell\n" or die "can't register root shell";
    exec 'chsh -s /bin/sash root';
    die "can't change root shell";
}