Archie search servers maintain file listings, updated monthly, of more than 1000 FTP sites containing nearly three million files. Any FTP server can register to be part of the Archie search service. The FTP site will then generate an ls-lr file containing a complete recursive listing of all the files on the archive. Archie will download these listings onto an Archie server and use them as a master index for remotely searching FTP sites.
You can search for a specific filename or regular expression using the archie client command as follows:
archie -s cat -h archie.unl.edu
This command searches the Archie server at archie.unl.edu for any files with a name that contains the string "cat" and outputs a listing (the UNIX "ls -lR" listing, to be exact) of the FTP sites and pathnames of these files. It's always good netiquette to search the archie server geographically closest to you.
You can also perform an Archie search via email. This is often more convenient because the results of the search are then sent to you as email. To perform the Archie search shown in the previous example via email, send an email message to email@example.com with the body:
set search sub find cat
Sending an email to an Archie server with only the word "help" in the body returns all of the information needed to use their archie client.