7z

If you're faced with a 7z file then you need a program like 7za to extract these archives. If your distribution has no 7z package you need to download the sources first:

# cd /usr/src/
# wget -c "http://sourceforge.net/projects/p7zip/files/latest/download"
...

Then extract the bz2 archive and change into the newly created directory:

# tar xf p7zip_9.20.1_src_all.tar.bz2
# cd p7zip_9.20.1/

Copy the appropiate makefile for your current architecture and operating system. Eg. I am using Slackware Linux 64Bit and I copied makefile.linux_amd64 to Makefile:

# cp makefile.linux_amd64 Makefile

Run 'make' to compile the sources and 'make install' to install the compiled binaries:

# make
...
# make install
...

The 7za binary (and manpages) will be installed under /usr/local so check for the 7za binary:

# ls -lah /usr/local/bin/7za
-r-xr-xr-x 1 root root 1.2M May 31 13:28 /usr/local/bin/7za*

Finally you can extract your 7z archive:

# 7za x archive.7z

7-Zip (A) [64] 9.20  Copyright (c) 1999-2010 Igor Pavlov  2010-11-18
p7zip Version 9.20 (locale=en_US,Utf16=on,HugeFiles=on,2 CPUs)

Processing archive: archive.7z

Extracting  archive.data

Everything is Ok

Size:       306897666
Compressed: 174812535