Re: /dev/tcp

On 2026-08-24 06:31, c186282 wrote:
> On 8/23/26 07:50, Carlos E.R. wrote:
>> On 2026-08-23 09:37, c186282 wrote:
>>> On 8/23/26 00:01, Rich wrote:
>>>> vallor <[email protected]> wrote:
>>>>> At Thu, 20 Aug 2026 23:30:40 -0000 (UTC), Lawrence D’Oliveiro 
>>>>> <[email protected]> wrote:


>>>    ANYway, /dev/tcp does have uses. It's worth exploring.
>>>    Maybe YOU can find a use to suit YOUR needs/desires.
>>>    I used it for a custom disk-scan/wipe app (had to
>>>    use a 'C' module because huge track/cluster/byte numbers
>>>    were needed for modern mag drives - the main app was
>>>    in Lazarus for the pretty display and buttons).
>>>
>>>    Note Lazarus/FPC *says* it supports huge seek numbers
>>>    but DOESN'T ... limited to maybe 4gb.
>>
>> I wrote a program that writes bytes on big partitions.
>>
>>
>> excerpted:
>>
>> const
>>       sourcefilename = './BigRandom';
>>       rawdest: string = '';     // example: '/dev/sda11'
>>
>>       shuflecount = 1024;
>>       arraysize = 1023;
>>       ChunkSz=1048576;
>> type
>>       tCacho= array [1..ChunkSz] of byte;
>>
>> var
>>     Fin, Fout: file of tCacho;
>>     gotresult: Word;
>>
>>     BigData : array [1..shuflecount] of tCacho;
>>     OutputIndex : Int64;    // counts MiB written.
>>
>>
>> begin
>>
>> // writes one MiB
>>        {$I-}write(Fout,BigData[RandomIndex]);{$I+}
>>        gotresult:= ioresult;
>>
>>
>> The purpose of the program is to fast fill a partition or disk with 
>> nearly true random data. It is as fast as dd could be.
> 
>    Um ... how many GB could that cope with ?

I have done entire disks sized terabytes. But I don't actually use "seek".

> 
>    'Seek' counts can sometimes be supplimented
>    by an 'offset' value - so basically you're
>    getting the mult of two doubles. I didn't
>    do it that way, and thus needed very large
>    sector/track/cluster integers. An external 'C'
>    pgm using really large integer types was needed.

Can you seek not a byte, but a record or array?

Seek(var F; N: Int64)

File can be a file of some variable that is not a byte. And

type Int64 = - 9223372036854775808..9223372036854775807;

(why signed?)

Why not QWord?

type QWord = 0..18446744073709551615;


>    Anyway, it worked.
> 
>    My app could ALSO just LOOK at data, kinda put
>    it into a "ghex"-looking sidebar (but with
>    ASCII translation if possible). So you could
>    just look, OR zap. Anyway, nothing TOO complex
>    aside from the sheer size of modern mag disks.
> 
>    As useful utility. I encourage people to write
>    their own.
> 
>    DID add one odd, maybe questionable, feature ...
>    you could spec on the CL x-number of gigs to
>    TOTALLY wipe at the beginning ... and then
>    a couple numbers for "shotgun" blasting of
>    later tracks. Most of the file-table/system
>    stuff tends to be early on, and data with
>    holes in it is "less useful". This made the
>    "wipes" much faster.
> 


-- 
Cheers, Carlos.
ES🇪🇸, EU🇪🇺;