Re: [Bug-tar] --concatenate bug?

[Helmut Waitzmann]

Sergey Poznyakoff <address@hidden> writes:

>David Ziman <address@hidden> wrote:
>
>> When using concatenate on an already created archive (foo.tar) and
>> specifying new files to "concatenate" as members to the archive
>> instead of specifying an archive to concatenate, in GNU tar 1.14 it
>> simply concatenates the file to the archive without verifying the
>> format of the archive or that it actually is an archive:
>
>Yes, this is known problem. It is in my todo list.

No, this is not a bug.  Tar shouldn't hesitate to concatenate that file,
if the user tells it so:  Maybe, one day there will be an extended tape
archive format which this gnu tar does not recognize as a valid archive.
In spite of it beeing totally correct to append such an extended tape
archive to an existing archive, this gnu tar would try to verify the
extended format, reject it and refuse to append it, thereby inhibiting a
user (who knows what he does) to get his work done.

As tar is a program mainly for system administrators, there is no need
for it to support do-what-I-mean-users, who don't read the manual
carefully.

At Sergey:  You shouldn't waste your time changing this feature.

If someone does not read the fine manual, then that's not your fault:
The manual clearly states, that the operation »--concatenate« will
concatenate archives, not add files as members to an archive.  If one
wants to add members to an archive, he or she should just use the
operation »--append« or »--update« rather than »--concatenate«.

To say it with a proverb of the programming domain: »If you lie to the
compiler, you'll get its revenge.«

However, there should be a reference in the manual from »--append« to
»--concatenate« and vice versa to make the reader become aware of the
difference.
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