Query about problem with updating software

[Bret Busby]

On 4/8/22 7:00 am, Colin Watson wrote:
> On Thu, Aug 04, 2022 at 02:26:42AM +0800, Bret Busby wrote:
>> On 4/8/22 2:19 am, Sarunas Burdulis wrote:
>>> On 8/3/22 13:45, Bret Busby wrote:
>>>> I am running UbuntuMATE 20.10 on this computer.
>>>
>>> 20.10 is no longer supported.
>>>
>>> https://fridge.ubuntu.com/2021/07/25/ubuntu-20-10-groovy-gorilla-end-of-life-reached-on-july-22-2021/
>>
>> I am fully aware of that.
>>
>> That does not answer, or, relate to the question, which, you conspicuously
>> omitted from your post, with the question being the purpose of this thread.
> 
> It is actually directly relevant though!  The reason your command
> doesn't work is that "sudo apt -y update" exits non-zero because of the
> various sources.list entries that return "404 Not Found", and as a
> result the other commands that you chained after it with "&&" never run.
> The reason that those entries return 404 is precisely because groovy is
> EOL and has thus been moved to old-releases.ubuntu.com.
> 
> https://help.ubuntu.com/community/EOLUpgrades#Update_sources.list will
> likely be helpful here.
> 
> (I presume that Software Updater flags the no-longer-present
> repositories as errors but is willing to go ahead and upgrade other
> things anyway, much as if you'd followed "sudo apt -y update" with ";"
> rather than "&&".  But you should fix the sources.list lines anyway.)
> 


Thank you.

I replaced the subdomain names with "old-releases", so 
"archive.ubuntu.com" and "security.ubuntu.com", became 
"old-releases.ubuntu.com", and, most of the errors were eliminated.

What is the difference between using ';' and "&&" in the chained 
command? I do know (or, believe) that the "&&" represents the logical 
"AND", but do not know what the ';'represents, unless it is simply like 
the end of an executable line, like in a 'C' program or a Pascal program.

-- 
Bret Busby
Armadale
West Australia
(UTC+0800)
..............