how to read file from sub-directories and do an average?

[Eric Schwartz]

There is no need for a temporary array:

foreach $inputdirname (sort readdir WORKINGDIR) {

No, but I have found that unless memory usage is a specific
optimization goal, temporary variables help tremendously in debugging,
and I will often use them even if they are not strictly required. I
could easly insert a

{
local $" = ', ';
print STDERR "inputdirs: [@inputdirname]\n";
}

block if I don't seem to be getting what I want to, or if I'm using
the debugger (mad props to Devel:tkdb!), set a breakpoint after the
readdir() call.

-=Eric