prob

When i am trying to
$uncompress tress.dmp.Z
I am getting tress.dmp.Z permission denied.

What action i have to perform to unzip or uncompress
It has rw-r--r-- permissions

When i am trying to change the permissions chmod 744 it says.
chmod: Warning: can't change tress.dmp.Z

Just checking whether my guess (i need permissions to uncompress it) is right ?

wheb u use gunzip or uncompress ... whatever ... u are trying to create a regular file from compressed file ;

I guess u are doing this uncompress operation in yr HOME dir or in the directory u have write permission ;

Copy the .Z file to your HOME and try uncompress and see the result ...