Can someone tell me how to make a directory in a Linux server password protected? What if all scripting is done in PHP? Is there any easy way to set it up so that a log-in screen automatically pops up? Is there any easy way like .htpasswd that pops up the screeen for you?

I know that
/etc/passwd
/etc/shadow
/etc/group
all exists...but where do I go from there? Maybe someone can point me to a good site?

Thanks!

if you're using linux of some flavor or another
stick this .htaccess file into the directory you're trying to protect

## .htaccess 
AuthName "Restricted Area"
AuthType Basic
AuthUserFile /some/directory/1.passwords
require valid-user

then add this 1.passwords file to /some/directory/

## 1.passwords
someuser: (ENCRYPTED PASSWORD)
anotheruser: (ENCRYPTED PASSWORD)

to generate the ENCRYPTED PASSWORD go here:
http://www.kxs.net/support/htaccess_pw.html

Does that totally ignore the /etc/ password and user information that is currently being used? or is the directory that you're suppose to indicate the one that is /etc/passwd ?