🚀 go-pugleaf

I asked 
1. why the Finder can't show the sizes (total contents in bytes) of folders, 
   like the old MFS finder did,
2. whether there is a desk accessory that does this, and
3. whether there is a desk accessory that can read and write the Finder's 
   Get-Info comments from the Desktop file.

Many people responded helpfully and I thank them all.  Summary:
   The Finder doesn't keep information about the total contents of a folder, 
only its immediate contents the next level down.  The only time it searches 
deeper is in response to a Get Info command.  Tracing through a whole 
subdirectory tree can be very time-consuming, so it makes sense for the Finder 
to do this only when specifically requested to.
   Rejoinder:  In the process of Getting-Info the Finder finds out the Whole 
Story on the subfolder structure of my folder of interest, but all it gives me 
in return for cooling my heels for however long it takes is one lousy number.  
Why can't it at least show the subtotals for each folder one level down?  That 
would be the equivalent of what the old MFS Finder showed in its View By Name 
window, which is all I asked for.  To be only a bit more visionary (Alan Kay 
eat your heart out), why can't it optionally show me the Whole Story - the 
complete tree as an outline-style list of folder names with their total bytes 
and number of files?  Presumably this would require a scrolling window to 
display; and it might also be nice to be able to print out the results or to 
save them as an Acta document.  Dreaming...

More summary:
   The current version of DiskTop, 3.0.3, has a Sizes button that will add up 
the total bytes in all subfolders.  This is essentially the same function as 
the Finder's Get Info except that if multiple folders and files are selected 
you get one number for the whole set rather than a number for each in separate 
windows.
   UTILITY-SHOWSIZES.HQX in the info-mac directory at sumex-aim is a shareware 
application by Jon Pugh that graphically displays the total sizes of all 
folders in a given folder.  (I.e. it only shows one level at a time, which is 
what I was asking for.)
   DiskTop now also allows you to attach (write and read) comments to 
individual files and folders.  Not the Finder's Get Info comments but a 
separate set, which is fine with me.  My check is in the mail!

Another question:
*Why* doesn't the Finder maintain a data structure with all the information 
about folder sizes?  Naively, it seems like all that would be needed is a 
linked list with one record for each file or folder, containing its current 
size and a pointer to the record for the next higher-level folder.  To update 
whenever somebody does a Save, it would have to read and modify x records, x = 
how deep the file is in the hierarchy.  Is that a lot of disk access?

Thanks again to all for their helpfulness!

- Dave Matthews
  ARPA:matthews@tcgould.tn.cornell.edu             BITNET:matthews@crnlthry
  USENET:...{cmcl2,shasta,uw-beaver,rochester}!cornell!batcomputer!matthews