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Subject : The way MTA handles comments inside archives
Target : BBS users
Date : 09-03-92
Rev. : 1.01 / 11-14/92
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Several questions have been asked about how to implement comments inside
archives. Some users reported failing comments (parts of the old comment
appended to a new comment).
When you run a BBS, you can expect a lot of different archives to be
uploaded, all with different comments inside. In fact there are two
kinds of comments:
- The archive-comment
Mostly an advertisement from the previous BBS, a bad way to inform
others that the file came from you. Better to include a file with
this information, because the comments are NOT compressed but the
file IS compressed;
- The descriptive comment
Most of the times, this is a file with a short description of the
archive (like the FILE_ID.DIZ standard). This TEC-note will not go
into this type of comments;
The archive comments CAN be used for something useful like a short
one-liner with information about the file. You can even combine the
one-liner with your own advertisement comment.
The key options that you must use are the AutoDescription option and
the CarryComment option. Both can be used together, but when used in
the wrong way, they can cause trashed comments inside the converted
archives.
- AutoDescription
This option will cause a standard advertisement to be added to the
converted files (as an archive-comment);
- CarryComment
This option will cause MTA to 'carry' the comment from either the
old archive or from FILES.BBS 'over' to the new archive. There are
a number of ways in which this can be done:
- Type 1 (CarryComment 1 or /CARCOM1)
MTA will take the comment from the original archive (up to 256
bytes) and will carry this over into the new archive. If you
have also set the AutoDescription, it will be appended to the
'carried' comment. Because most 'source' (or original) archives
contain an adversisement (sometimes with ANSI sequences) and
these files can vary in length from 100 bytes to several K's of
information, it is almost sure that the new comment in the
converted archive will contain only a PART of the original archive
AND (optionally) your own advertisement. This will look like trash
(a partially displayed comment and your own complete comment).
In general, there is NO usage for CarryComment type 1 unless you
know for sure that all comments in the original files should be
maintained (in which case they can not exceed 256 bytes of info);
- Type 2 (CarryComment 2 or /CARCOM2)
This is also a tricky one and should only be used of files you
created yourself. Type 2 will take the comment from the original
archive and store up to 256 bytes. Then it will convert the
archive and after conversion, MTA will look if there is a
description inside FILES.BBS for this file. If there is, this will
replace the comment from the original archive, if there isn't, the
original comment is used.
If you use this type (type 2) for uploaded files of various kinds,
you are bound to get a number of trashed archives. Some of the
uploads will contain FILES.BBS entries but some won't. These last
types will get a comment just like CarryComment Type 1 (part of
the original comment plus, optionally, your own advertisement);
- Type 3 (CarryComment 3 or /CARCOM3)
The right way for all situations. MTA will not 'carry' the comment
from the original file over into the new file but if there is an
entry in FILES.BBS it will take this entry and WILL 'carry' it
over into the new archive. Your own advertisement will be appended
to the comment and you will get something like this:
1> /------------------------------------------------------------\
1> | This came from DISP HQ 2:512/100 - Multiline Paradise |
1> \------------------------------------------------------------/
2> A very dynamic archive conversion program
1> came from your advertisement file and 2> came from the FILES.BBS
file. You can also make something like this:
1> /------------------------------------------------------------\
1> | This came from DISP HQ 2:512/100 - Multiline Paradise |
1> \------------------------------------------------------------/
1> A short description of the archive below:
1>
2> A very dynamic archive conversion program
1> came from your advertisement file and 2> came from the FILES.BBS
file. The advertisement file already contains the entry that will
inform your users that the description of the file is below the
advertisement.
If you want to store your archives on diskettes and keep a catalog
of these diskettes with CATDISK <tm> (a very good program), you
should not use the advertisement file. In that case CATDISK can
take the description from FILES.BBS, which is carried over into
your archive, and put this comment into the CATDISK database;
In general, you should try some of the options before you start the
conversion on large numbers of files. A few rules about advertisement
files and advertisements in general (I am a BBS USER you know):
- Don't use ANSI in advertisements. Most archive programs won't allow
a direct display of ANSI (keeps out trojan horses), so most of the
time it will look like trash;
- Keep the advertisements short. As said before, the comments inside
the archives are STORED (NOT compressed). Better to make a short
advertisement with something like this:
[ This file came from Users Delight, see USEDEL.TXT for more info]
And include USEDEL.TXT into the archive (in most of the cases, this
file will be COMPRESSED and NOT stored). This is better for you users
who don't have fancy MNP/LAPM modems and/or turbo-blasters but still
use ye'oll 2400 (or less) baud modems and for you to, because the
uncompressed comments, in general, take more disk-space than the
compressed advertisements.
- Only use the lower character-set (X'00'-X'127') if you know that
your files can be transferred to other platforms.
If MTA carries descriptions in the FILES.BBS-alike file into the
archive, it can (and will) strip files-counters from the decriptions.