Longlist files without expanding

Hi, I want to long list files within a file.tar.Z/file.tar.gz file. I tried these:
I'm working on HP UX 11iV3 OS

 tar -tvzf file.tar.gz -->not working as 'z' is not supported
gunzip -c file.tar.gz | tar tvf - -->does this unizip the tar file? i don't want it to be unzipped.
 

Appreciate any help. Thanks.

No it does not change the file. It has to unzip the file to read it. gunzip -c means to expand the file to stdout, not to a disk file.