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Next: 4.2 Other access methods Up: 4 Archives and access Previous: 4 Archives and access

4.1 ftp

The most common access method is still ftp. The name ftp (file transfer protocol) stands for the protocol type as well as for the software program of the same name, which is part of every common UNIX system and available for most other computers. (Note that you need to be connected to a TCP/IP network.) Please read your local description of the ftp facilities before you start. And please remember that these services are usually free of charge for you, but your site is charged for the data transfer.

Every machine in the world has a unique IP (Internet Protocol) identification number, consisting of four numbers, separated by periods. This IP identification matches a machine name (host name). Therefore, using the IP identification or the machine name should work equally well. If you have ftp access, simply use the command

ftp hostname or ftp IP-No to connect to the chosen site and download the files or programs of interest.

If not mentioned explicitly, the username to use is anonymous. Often, the username ftp is also accepted. Then, you are usually requested to give your full Email address as the password. This is helpful in case of problems or to document the usage of the server. Some sites check if your specified account/password exists.

Here is an easy example of how one could retrieve the file containing the riverflow data from the so--called statlib archive in the US.

 

 
 ftp lib.stat.cmu.edu  
 login: anonymous  
 password: myusername@mysite  
 cd datasets 
 dir 
 get riverflow  
 bye

IMPORTANT: There are two modes for data transfer, text or ascii mode, usually the default, and binary mode. Remember that files with suffixes .zip, .arc, .Z, .gz, and .tar are archives which have to be extracted with programs like unzip, arc, uncompress, gunzip, or tar. These are binary files! Enter the command binary, before starting the file transfer. Usually, setting the mode to binary should not have any effect on text files. If you run into problems, such that you can not read text files properly, or the program to extract the original files abandons with an error message, it is likely that the transfer mode caused the problem.

If you don't have access to ftp, you can still obtain files from ftp archives. You have to send the commands you want to use (e.g., cd /pub or dir) to the server, which interprets your commands and sends the output back to you. For details, see the description ''Accessing the Internet by E-Mail'' written by Bob Rankin. This document describes also how other services like WWW or gopher can be used via Email.

You can have it sent to your Email address by sending the message
GET INTERNET BY-EMAIL NETTRAIN F=MAIL
to listserv@ubvm.cc.buffalo.edu (send neither any other text nor a subject).
It is also available via ftp from ubvm.cc.buffalo.edu by using the commands
cd NETTRAIN and get INTERNET BY-EMAIL.



next up previous
Next: 4.2 Other access methods Up: 4 Archives and access Previous: 4 Archives and access



Andreas Krause
Mon May 15 19:18:23 MET DST 1995