Subj : sweep
To   : Eddy Thilleman
From : Lesha Tsoorgaev
Date : Mon Mar 19 2001 03:55 am

Hello Eddy,

On 15/Mar/01 at 11:55 you wrote:

ET>>>> Borland Pascal as DOS .EXE file and compiled it with Virtual
ET>>>> Pascal/2 v2.1 build 243 as OS/2 .EXE file, and implemented it
ET>>>> also in REXX.

 ET>     FindFirst('*', Directory, DR);
 ET>     while (DosError = 0) do
 ET>     begin
 ET>       if (DR.Attr and Directory) = Directory then
 ET>       begin
 ET>         if ((DR.Name <> '.') and (DR.Name <> '..')) then
 ET>         begin
 ET>           ChDir( DR.Name );
 ET>           AllDirs;
 ET>           ChDir( '..' );
 ET>         end
 ET>       end;
 ET>       FindNext( DR );
 ET>     end;

 ET>   Call SysFileTree path || "\*", 'dir', 'D'
 ET>   if datatype( dir.0 ) <> "NUM" then dir.0 = 0
 ET>   do f = 1 to dir.0
 ET>     name = substr( dir.f, 38 )
 ET>     if (substr( dir.f, 32, 1 ) = 'D') then    /* directory? */
 ET>       call Exec( name )
 ET>   end

 ET> The DOS pascal version is equally fast as the REXX version, the 
 ET> OS/2 VP/2 version is slower (as I said).

I think it is possible, that SysFileTree and OS/2 DOS support are simply 
caching directory search and do not call DosFindFirst/DosFindNext for every 
filename. These functions allow to request information about ~64K filenames at 
once, and IMHO this can result in speeding up the process greately.

While SysFileTree is obviously must use such a technique, I am in doubt if OS/2 
DOS support does so actually. Try to replace running external programs with 
somewhat fast enough (may be without any output) to figure out if the main 
brake is FindFirst/FindNext or not.

Cheers,
\Lesha

--- MadMED v0.42i/OS2 (Apr 25 1997 15:17:26)
 * Origin: HDD2G/HPFS+HDD32M/RT-11 (2:5020/1613)

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