This example restricts access to users on two particular systems or hosts. This approach is often useful if you want to restrict access to workers in a small group and know the the addresses of the desktop systems or workstations they use. This example allows access from the central Unix systems of Hopper and Alberti but restricts access from Christa. That probably does not make logical sense, since someone normally has an account on all three, but it allows you to easily demonstrate that you understand how the procedure works.

Here's the recipe:


Create the .htaccess control file using 
your editor of choice, e.g., pico.
Remember, Unix files that begin with a dot 
are special and do not show up in normal listings 
but require the "a" switch, as in:
     % ls -al
OK, put the following in the 4-line .htaccess 
file.  Each line begins in column 1. Exact case
and spacing matter: 

     order deny,allow
     deny from all
     allow from 132.177.137.8
     allow from 132.177.137.21

1st line indicates that deny directives come first, 
    followed by any allow directives.
2nd line indicates the default is to deny everyone.
3rd line makes an exception to allow access from
    "132.177.137.8" which is the IP address for 
    hopper. That means anyone using Lynx on that 
    system would have access. 
4th line makes an exception to allow access from
    "132.177.137.21" which is the IP address for 
    alberti. That means anyone using Lynx on that 
    system would have access.

NOTE: IP addresses can be obtained by issuing the 
UNIX command of the form:
     % nslookup hopper.unh.edu

Copy this file into the directory to be protected
and give it world-read access:
     % chmode go+r .htaccess
     % ls -al

Test it to make sure it works.  You should find it
works with Lynx if you login to Hopper and Alberti,
but not if you login to Christa.