Subject: Re: Here-Scripts in bash (fwd)
From: [email-masked] (Jonathan Lanier)

11 Apr 1997 15:04:46 -0700
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My 2 cents:

> on average.  In contemporary PCs, assuming an average of 2 cycles per
> instruction, a 166MHz pentium can execute about 250 instructions
> in 3 microseconds.  In an application that does creation/destruction
> of temp files all the time or for every transaction, it is
> just not something that one would say is elegant to be inserted
> into the loops.

Er, what about the tens (possibly hundreds) of thousands of instructions 
that occur just from calling the OS file open API function?  And the 
overhead for reading/writing disk sectors?  Seems to me that 3 
microseconds is trivial enough to be close to zero, for all practical 
assumptions.  The argument falls apart in both cases:

1) You don't make very many temp files.  Overhead is therefore not important.
2) You DO make lots of temp file very frequently, in which case the OS 
overhead for file creation/deletion is WAY worse than an environment 
lookup (less than 0.1%).  So overhead is still not important.

First important rule of code optimization is only optimize the inner 
loop:  i.e. don't waste time (and code portability) to save cycles when 
they won't be visible.

Personally, I think since the TEMP variable is a standard on the Win32 
platform, that the GNU tools should adhere to that standard when they are 
being compiled to run natively on that platform.  I find the need for 2 
temp directories quite annoying.  Also what if I don't want to use C: for 
my temp directory?  What if I have a separate partition, on a faster hard 
drive, and I want all my temp files placed there instead?  I can think of 
no logical reason for NOT using the TEMP environment variable.  It just 
makes sense.

- Jonathan Lanier
  [email-masked]

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