Re: /dev/tcp

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:
>>>
>>>> On Thu, 20 Aug 2026 18:15:27 -0000 (UTC), Eli the Bearded wrote:
>>>>
>>>>> In comp.os.linux.misc, Lawrence DOliveiro <[email protected]> wrote:
>>>>>>
>>>>>> On Thu, 20 Aug 2026 00:59:41 -0000 (UTC), Eli the Bearded wrote:
>>>>>>>
>>>>>>> This came up in the context of "how to test network on a system
>>>>>>> with no root and no helpful utilities installed."
>>>>>>
>>>>>> So a version of bash that supports /dev/tcp is somehow excluded
>>>>>> from that “no helpful utilities installed” assumption?
>>>>>
>>>>> The system being tested did not have bash installed. Busybox
>>>>> provided /bin/sh there.
>>>>
>>>> I thought you said you were testing the *network*, not the *system*.
>>>>
>>>> You can’t really do that (in general) without access to a proper
>>>> suite of diagnostic tools.
>>>>
>>>> In such a situation, I would try one (or both) of two things:
>>>>
>>>> * Reboot the machine with a SystemRescue USB stick
>>>>    <https://www.system-rescue.org/>. That way, I get unconstrained
>>>>    access to an entire system custom-designed precisely for running
>>>>    diagnostics.
>>>> * Bring in my own machine, which already has my own custom setup on
>>>>    it, and connect it to the network.
>>>>
>>>> Both of these also have the advantage of ruling out screwups in the
>>>> existing OS installation.
>>>>
>>>> And if you’re saying the situation would not allow me to do either of
>>>> these things, then I would not have accepted the job in the first
>>>> place.
>>>
>>> Have you ever agreed with someone?
>>
>> It's kind of the troll ethos, disagreeing brings on more chaos.
> 
> 
>    There are always a few ... being negative/disagreeable
>    or, worse, All-Superior is Their Main Thing. They feel
>    they "Gain Power" that way.
> 
>    No, I'm not basing that on Freud or Jung - just long
>    experience.
> 
>    I pref the "Let's All Get Along" approach. Everything
>    goes MUCH smoother and solutions, rather than conflict,
>    is the usual result.
> 
>    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.



-- 
Cheers, Carlos.
ES🇪🇸, EU🇪🇺;