[TUHS] Traditional method of dealing with embedded shar files

Richard Salz rich.salz at gmail.com
Tue Jul 21 04:08:23 AEST 2020


shar, by the way, stands for "shell archive."  That is, it's an archive
that could be unpacked by feeding the file into sh.
The most complete unshar is probably at
http://sources.vsta.org/comp.sources.unix/volume15/cshar/  It's portable C
(for its time, 20 years ago). Safety, in terms of not trashing an existing
file, was a goal.


On Mon, Jul 20, 2020 at 1:59 PM Warner Losh <imp at bsdimp.com> wrote:

>
>
> On Mon, Jul 20, 2020 at 11:54 AM Clem Cole <clemc at ccc.com> wrote:
>
>>
>>
>> On Mon, Jul 20, 2020 at 1:25 PM Will Senn <will.senn at gmail.com> wrote:
>>
>>> My questions for y'all are how would you go about doing this? Use vi to
>>> delete everything through the ==== cut here line?
>>>
>> Yep
>>
>>
>>
>>
>>> In my world, if I screw something up, it's 15 seconds to run a restore
>>> script in my simh directory and I can try again, so my level of concern for
>>> a mistake is pretty low. If I was doing this in 1980, on real hardware, I
>>> would have had many concerns, as I'm sure some of y'all can remember, how
>>> did you prepare and protect yourselves so a patch was successful.
>>>
>> Run an incremental backup and/or copy the files you new you we were
>> messing with.  The good news was that patch makes backups.
>>
>>>
>>> BTW, I thought .shar was an archive format, so when I saw the patch was
>>> a shar file,
>>>
>> It was so of.  It was a way to send files around that people could easily
>> execute and you new would work through 7-bit based email which is all the
>> SMTP guaranteed in the early days.   Yeh but .. uucp was 8 yep.  But
>> some of the legs of the USENET were luck to be based on Arpanet site, which
>> might have had a mailer running BITNET.  When shar was created the 'least
>> needed' style assumptions were used.   As it was it was often that people
>> put tarballs, then compressed them and then uuencoded them inside.  Often a
>> space savings and made it easier -> compressed tar was pretty good, and
>> even with the 3 8-bit chars as 4 6-bit chars of uuencode it will worked out
>> well in practice.
>>
>
> There's various 'unshar' programs, but they are all just restricted
> versions of the shell because of the wide diversity of 'shar'
> implementation...  uuencoded compressed tar balls added another layer to
> this mess as well :)
>
> Warner
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://minnie.tuhs.org/pipermail/tuhs/attachments/20200720/e346e1fd/attachment.htm>


More information about the TUHS mailing list