#! /usr/bin/perl

# update-stow --
# $Id$
# Carlos Duarte <cgd@mail.teleweb.pt>, 990116

# 
# this script is to be run on a crontab, or something, and
# it is to mantain a stow package...
# 
# it is somehow hardcoded
# 
# operation mode: 
# . keeps a stamp file, that keeps a count, and its modification time.
# . if any package under stow is newer than mod time, then it is stowed
# . if count is reached, all packages are stowed
# 
# so, the things to define, are: 
# . $stamp_file = "/usr/local/.stow_stamp", where stamp file lives
# . $stow_dir = "/SHARE/os-stow", eg: /SHARE/irix-stow, where packages lives
# . target dir, this is hardcoded on stow invocation.  currently, there are
#   two targets: 
#     . /usr/local, for "normal" packages
#     . / (root), for dotted started packages
# 
#   for instance, "stow-1.3.2" will be stowed into /usr/local, but
#   ".dosemu-0.66.7" will be stowed to root
# 
#   this is to make happy pacakges that wants files under specific
#   locations, like /etc and /usr/X11*, for example
# 

sub get_time {
	local($file) = shift; 
	return (stat($file))[9]; 
}

sub put_time {
	local($file) = shift; 
	open(F, $file); 
	local($n) = <F>; 
	close(F); 
	chop $n; 
	open(F, ">$file"); 
	printf F "%d\n", $n+1; 
	close(F); 
	# system("touch $file"); 
}

sub get_count {
	local($file) = shift; 
	local($n); 
	open(F, $file); 
	$n = <F>; 
	close(F); 
	chop $n; 
	return $n+0; 
}

sub reset_count {
	local($file) = shift; 
	open(F, ">$file"); 
	print F "0\n"; 
	close(F); 
}

$stamp_file = "/usr/local/.stow_stamp"; 
if ( -e $stamp_file ) {
	$stamp_time = &get_time($stamp_file);
}

$os = `uname`; 
$os =~ tr/[A-Z]/[a-z]/; 
$os =~ tr/[a-z]//dc; 
$stow_dir = "/SHARE/$os-stow"; 

if (&get_count($stamp_file) > 336) {
	opendir(D, $stow_dir) || die; 
	for $file (readdir D) {
		($file eq ".") && next; 
		($file eq "..") && next; 
		push(@args, $file); 
	}
	&reset_count($stamp_file); 
} else {
	if (&get_time("$stow_dir/.") < $stamp_time) {
		goto _END; 
	}

	opendir(D, $stow_dir) || die; 
	for $file (readdir D) {
		($file eq ".") && next; 
		($file eq "..") && next; 
		if (&get_time("$stow_dir/$file") > $stamp_time) {
			push(@args, $file); 
		}
	}
}
closedir D;

if (scalar(@args) > 0) {
	@local_ones = grep(!/^\./, @args); 
	@root_ones = grep(/^\./, @args); 
	if (@local_ones+0) {
		$cmd = 
		sprintf("cd %s && /usr/local/bin/stow -v -t /usr/local %s", 
				$stow_dir, join(' ', @local_ones)); 
		system($cmd); 
	}
	if (@root_ones+0) {
		$cmd = 
		sprintf("cd %s && /usr/local/bin/stow -v -t / %s", 
				$stow_dir, join(' ', @root_ones)); 
		system($cmd); 
	}
}

_END: 
&put_time($stamp_file);