The PC Primer: The Internet: HTML

File Transport Protocol

HTML

There is an enormous amount of software available for download and File Transfer Protocol allows you to transfer data to and from remote computer systems. Usually the user transferring a file needs authority to login and access files on the remote system. The common facility known as anonymous FTP actually works via a special type of guest account running on the remote system. Files are transferred in two formats Binary and ASCII, although to the user the type of file being transferred is irrelevant as the file type will be automatically set by the browser, however sometimes things go wrong and you may see what appears to be garbage on the screen after a file transfer, this is almost certainly machine code (Binary)

Binary file type

Files of this type are invariably one of the following:

Programs, either raw or compressed (zipped)
Images
Audio files
Video Files

ASCII

Stands for American Standard Code for Information Interchange, These are:

Site index files
html documents
Documentation files

Bear in mind that a large majority of sites are based on servers running the UNIX operating system. UNIX is case sensitive so if for example the URL is stated as http://www.dodgyboots.ac.uk, then HTTP://WWW.DODGYBOOTS.AC.UK will not work.

Command line FTP

Here we see a command line FTP session, it's available on your PC. At the command prompt the command o (open) ftp.hudson.home (the name of the server) is typed. You're then asked to log in and type your password, which does not appear on the screen. The command dir (directory) will show the files in that directory.
Files are transferred by 'get' and 'put' commands, as in get index.txt or put c:\temp\uploadthis.txt. multiple files are moved with mget or mput filename

FTP commands

! - Runs the specified command on the local computer
? - Displays descriptions for ftp commands
append - Appends a local file to a file on the remote computer
ascii - Sets the file transfer type to ASCII, the default
bell - Toggles a bell to ring after each file transfer command is completed (default = OFF)
binary - Sets the file transfer type to binary bye - Ends the FTP session and exits ftp
cd - Changes the working directory on the remote computer
close - Ends the FTP session and returns to the command interpreter
debug - Toggles debugging (default = OFF)
delete - Deletes a single file on a remote computer
dir - Displays a list of a remote directory's files and subdirectories
disconnect - Disconnects from the remote computer, retaining the ftp prompt
get - Copies a single remote file to the local computer
glob - Toggles filename globbing (wildcard characters) (default = ON)
hash - Toggles hash-sign (#) printing for each data block transferred (default = OFF)
help - Displays descriptions for ftp commands
lcd - Changes the working directory on the local computer
literal - Sends arguments, verbatim, to the remote FTP server
ls - Displays an abbreviated list of a remote directory's files and subdirectories
mdelete - Deletes one or more files on a remote computer
mdir - Displays a list of a remote directory's files and subdirectories
mget - Copies one or more remote files to the local computer
mkdir - Creates a remote directory
mls - Displays an abbreviated list of a remote directory's files and subdirectories
mput - Copies one or more local files to the remote computer
open - Connects to the specified FTP server
prompt - Toggles prompting (default = ON)
put - Copies a single local file to the remote computer
pwd - Displays the current directory on the remote computer (literally, "print working directory")
quit - Ends the FTP session with the remote computer and exits ftp (same as "bye")
quote - Sends arguments, verbatim, to the remote FTP server (same as "literal")
recv - Copies a remote file to the local computer
remotehelp - Displays help for remote commands
rename - Renames remote files
rmdir - Deletes a remote directory
send - Copies a local file to the remote computer (same as "put")
status - Displays the current status of FTP connections
trace - Toggles packet tracing (default = OFF)
type - Sets or displays the file transfer type (default = ASCII)
user - Specifes a user to the remote computer
verbose - Toggles verbose mode (default = ON)