Zip

zip provides classic zip compression. It is handy for cross-platform compatibility with Microsoft operating systems. Newer versions of zip include support for Unicode and encryption. These can be enabled or disabled at built time on Gentoo systems by their respective USE flags (see below).

The equal and opposite program to zip is unzip, which is included in a separate package.

Emerge
After adjusting USE flags:

Optionally  for unzip capabilities (see the unzip article for more information).

Environment variables
zip does not have any configuration files, however its operation is modifiable by the following environment variables:


 * ZIPOPT - Can be used to set any option for the command.
 * ZIP - Does the exact same thing as the ZIPOPT variable (directly above).
 * Zip$Options - For RISC OS use. Does the exact same thing as the ZIPOPT variable (directly above).
 * Zip$Exts - For RISC OS use. Contains extensions separated by a   (colon) that will cause native filenames with one of the specified extensions to be added to the zip file with basename and extension swapped.
 * ZIP_OPTS - For VMS use. Does the exact same thing as the ZIPOPT variable.

External resources

 * How are zlib, gzip and Zip related? What do they have in common and how are they different? (stackoverflow.com)