rich@bvax.UUCP (Rich Chahley) (08/07/87)
I'm having trouble extracting ...tar.Z files off of The CONSULTANTS' EXCHANGE
(uucp: conexch 714-842-5851 login: nuucp). I can successfully download files
such as "emacs38.tar.Z" but cannot extract the files from the "tar" format.
This is what happens....
To decompress, I use ---> compress -d emacs38.tar.Z
resulting file is ----> emacs38.tar
To extract, I use ------> tar xvf emacs38.tar.Z
resulting messages are.... tar: blocksize=20 (normal message)
.... tar: directory checksum error
This problem has consistently happened on all ...tar.Z files downloaded from
this bulletin board. I am running a IBM PC-AT with SCO XENIX 2.2.1.
Has anyone experienced similar problems?
Is there something that I'm doing wrong?
The compress program I am using is Ver 4.0 (85/07/30) BITS=16
I would appreciate any help (and I'm desperate to start tying these programs).
Thanks in advance....
Richard Chahley
{allegra, ihnp4, decvax, pyramid, watmath} !utzoo!bnr-vpa!bnrnuns!ngpt!richbrian@ncrcan.UUCP (Brian Onn) (08/11/87)
In article <249@bvax.UUCP> rich@bvax.UUCP (Rich Chahley) writes: > >I'm having trouble extracting ...tar.Z files off of The CONSULTANTS' EXCHANGE >(uucp: conexch 714-842-5851 login: nuucp). I can successfully download files >such as "emacs38.tar.Z" but cannot extract the files from the "tar" format. ... > resulting messages are.... tar: blocksize=20 (normal message) > .... tar: directory checksum error > >Richard Chahley >{allegra, ihnp4, decvax, pyramid, watmath} !utzoo!bnr-vpa!bnrnuns!ngpt!rich I came across this same problem, when I realized what was causing it. I (and I suspect you are) was using a xmodem protocol to download the file. Unfortunately, xmodem does not create files that are the *exact* length of the file downloaded, but are actually multiples of 128 bytes (the xmodem blocksize). Compress will uncompress the file without complaining, but the resulting tar file is longer than it should be. Thus tar will try to read some data at the end of the tar file, but it doesn't make sense...hence 'directory checksum error'. The trick is to download a compressed tar file with a protocol that properly retains file sizes after the download. I use YMODEM, with 1k block sizes, and have downloaded,uncompressed, and 'untarred' with no problems ever since. I don't know whether or not kermit maintains file sizes, but I didn't have much luck with kermit and compressed tar files. Hope this helps,