# This is a work in progress!
# NOT FOR THE FAINT OF HEART
# Multi-process multi-host log with distributed configuration
# In this example
#    Jon and Tom both get their own logs and config files
#    CGI accesses receive thier own log
#    Images get their own log
#    Everything else is logged to the usual place
# Current Caveats
#    -u likely cannot be used, since flog needs to setuid
#      (which washes out to be roughly the same...) perhaps -g as well
#    you should read man Safe
#    User logs should: preexist, not be opened for clobber else may be owned by user running flog (root)...

#add 3rd option to FILES to decide what user to open as? (this req's forking in flog itself :-(

use Safe;
sub spawn;

my($user, $comparment, %OENV);
my %FILES= (
	    IMAGES=>[">>/var/log/httpd/images.log"],
	    TOM=>[">>/home/tom/access.log"],
	    JON=>[">>/home/jon/access.log"],
	    CGI=>[">>/var/log/httpd/cgi.log"],
	    CATCH=>[">>/var/log/httpd/access.log"]
	    );
%OENV=%ENV;
undef %ENV;
foreach $user ( qw(tom dick harry) ){
    #Sandbox the user
    $compartment{$user} = new Safe $user;
    die($compartment);
    $compartment{$user}->rdo("~$user/.flog.pl");

    #Make flog aware of the files
    foreach $key ( keys %{$user::FILES} ){
	$FILES{"{$user}::{$key}"} = ${$user::FILES}{$key}; }
}
%ENV=%OENV;


sub flog{
    print CGI if m% /cgi-bin/%;
    if( m%tom\.com$% ){
	return spawn sub { &flog::become("tom", "tom");
			   $compartment{"tom"}->reval("&flog()"); }}
    if( m%dick\.org$% ){
	return spawn sub { &flog::become("dick", "friend");
			   $compartment{"dick"}->reval("&flog()"); }}
    if( m%harry\.net$% ){
	return spawn sub { &flog::become("harry");
			   $compartment{"harry"}->reval("&flog()"); }}
    # Return if you do not wish to duplicate data across logs
    print CATCH;
}

#Straight from perlipc
sub REAPER {
    wait;
    $SIG{CHLD} = \&REAPER;  # loathe sysV
}

$SIG{CHLD} = \&REAPER;
sub spawn {
    my $coderef = shift;

    unless (@_ == 0 && $coderef && ref($coderef) eq 'CODE') {
	die("usage: spawn CODEREF"); }

    my $pid;
    if (!defined($pid = fork)) {
	return; }
    elsif ($pid) {
	return; } # I'm the parent
    # else I'm the child -- go spawn

    #open(STDIN,  "<&Client")   || die "can't dup client to stdin";
    #open(STDOUT, ">&Client")   || die "can't dup client to stdout";
    ## open(STDERR, ">&STDOUT") || die "can't dup stdout to stderr";
    exit &$coderef();
}

1;