Re: [MacPerl] Folder recursion and recognition problem

[hal@dtor.com (Hal Wine)]

>At 1:02 PM -0500 03/06/96, Hal Wine wrote:
>>This means you should either:
>>a) do a chdir() to the supplied directory, then always do an opendir()
>>on the current directory (':' for Mac, '.' for unix/dos).  Or,
>>b) always prepend the directory to the filename returned by readdir().
>>
>>My hunch is (a) runs faster on the Mac (due to internals of the Mac
>>file system), and no slower on other file systems.
>
>No, according to Matthias, a) shouldn't run faster. He said MacPerl fully
>expands relative pathnames to absolute pathnames before doing anything with
>them.

Well, I hate to disagree with Matthias, but (a) DOES run faster, and
works correctly, while (b) has bugs. (See attached script)  Here's the
timing for 10,000 stats of a directory where the path string is 223
characters, and 7 levels deep (excluding volume name):
    Perl 5.0.7r1m:
      194 seconds for full path stat
      120 seconds for relative stat
    MacPerl 4.1.8:
      200 seconds for full path stat
      126 seconds for relative stat

So, we see that using a full path is about 60% slower than relative directories.

Using a full path is limited to strings of less than 256 characters,
and, there are some wierd things that happen at the extremity of that
limit.  In the attached script, the name of the final directory created
gets truncated, without any error notice, in both MacPerl 4 & 5.

I'm not sure when the conversion from relative to full path occurs.  I
tried combinations such as '::' and ':dir:dir' to see if I could force
it, and I couldn't.

Anyway, a very ugly test script is attached, purposely designed to show
how NOT to write perl code ;-)  If you use it, be sure to change the
name of your test volume at the top of the code....



Attachment converted: ION2:dir test (TEXT/McPL) (0000C679)
--Hal
Hal Wine <hal@dtor.com>     voice: 510/482-0597