Changing $0 to display readable information in ps output

ps(1) output in a build cluster node is very noisy because there are
many wrappers and long command lines. Setting Iurt's $0 to a short
summary makes it easier to understand what's going on. Additionally,
wrapper scripts can be changed to exec the wrapped utility in the
same process to further remove noise from the process list.

Example of ps output:

 9231 ?    S    0:00 sshd: mandrake@notty
 9232 ?    Ss   0:00 Iurt: cooker i586  @73504:perl-IO-All-0.35-3mdv2007.0
 9242 ?    R    0:05 tar xf /export/home/mandrake//chroot_cooker.i586.tar

1 files changed, 5 insertions, 0 deletions

diff --git a/iurt2 b/iurt2
index 94f6d49..f0457c4 100755
--- a/iurt2
+++ b/iurt2
@@ -510,6 +510,11 @@ do {
     $rebuild = 0;
     foreach (my $i ; $i < @{$run{todo}}; $i++) {
 	my ($dir, $srpm, $status) = @{$run{todo}[$i]};
+	
+	# Set argv[0] (in the C sense) to something we can easily spot and
+	# understand when running ps	--claudio
+	$0 = "Iurt: $run{distro_tag} $run{my_arch} $run{media} $srpm";
+
 	$status or next;
 	$done{$srpm} and next;
 	$done{$srpm} = 1;