.tar.gz problems
 

i downloaded a .tar.gz file. i decompressed it via the tar xvzf <filename>.tar.gz command. just curious if this type of decompression can alter the decompressed files.

I am sure it won't alter anything. .tar.gz is a two step process as you know. You first archive or tarball it using Tar command. It makes only a huge archive of the folder with all the directory structure intact. Then you use gzip command to compress it.

Personally what I do with these .tar.gz file is this ...

$gunzip -c filename.tar.gz | tar xvf -

It never fails and doesn't alter anything...

Hope that helps... :)