while (<>) {

chomp $_;  #defined by a list if directories piped in

chdir $_;

system " run prog";

chidr .. }
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I've been leaning on this for program execution in a heavy production enviornment ( Solaris and NT ) for about two years now.. I've had half a dozen incidents ( NT only ) of the launched process getting 'lost' and not returning ( Never in production only Unit and Test ). It gives me good flexibility for both input and output.