Utility to detect and give info of compression method of a file
 

What is utility tool to detect and give info of compression method (preferably more info) in any mean (CL or GUI) ?

IOW what windows 7z tool equivalent for Linux ?

#1 you might want to look into the "file" command, that will use the magic number signature or character in the first bytes of the file to identify the file type. If it is compressed, it reports the compression.

#2 7-zip should be in your repositories. Search for 7zip or p7zip, these implement the 7z compression and decompression.