UNIX for Dummies Questions & Answers

While trying to gunzip afile I get the following error message

ls -l UK_US_02310.dat.gz
-rwxrwxrwx 1 imis abint 348854527 Jan 8 00:17 UK_US_02310.dat.gz

gunzip UK_US_02310.dat.gz

gunzip: UK_US_02310.dat.gz: invalid compressed data--format violated


I can gzcat the file and pipe to a file but it coredumps after 230k of records . I know there are 12952988 records in file

Is there anyway of fixing the file or extracting the data minus the corrupt part or have I lost all the data

I have 2 ideas based on problems I've had with gzip. I don't know if either is the case you're running into, but both are worth checking out.

1. Could it be that your file hits 2 GB in size at the 230k records mark and that is what chokes gunzip? I think I remember seeing where gunzip (maybe just some versions of it) can't handle largefiles properly.

2. Also check the versions. On a Solaris box I once had a problem where the version of gzip on that box was different than the gzip on the box I transferred the file from and that caused problems. Installing the same version both places took care of that issue.

Good luck.

I don't think it is a problem with the size as we have files larger than 2 gigs .

I have also tried cat file |gunzip >a but this fails with the same error. I remember getting this error on windows and I used an app to reconstruct the file but I can't find it for unix

Did you create the file or did you ftp it from somewhere? I think you could get this error if you downloaded the file in ascii mode instead of binary mode...

What version of gunzip are you using? FYI, you can download the latest version of gzip here and try it with that...

Also, see if this helps: http://www.gzip.org/recover.txt