FTP

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See also: Data | Internet | FTP Clients | Protocols

Acronym: File Transfer Protocol

FTP is a protocol and method for sending and receiving files and can be a file sharing tool. FTP is a client/server protocol that was the first widespread means of readily transferring files electronically. FTP was therefore the first technology with which it was practical to download large quantitites of data over a TCP/IP network and it remains an extremely fast and extremely efficient transfer method.

FTP Clients are one of the easiest tools and are ubiquitous, existing on almost in almost every computer you can purchase. Because of its simplicity, you have always had one and never knew about it. Nearly every Internet-connected system from Windows to BeOS and every flavor of UNIX has an FTP client, making it one of the great, lasting interconnective technologies.

Servers

FTP is a server-based system. You must connect to some central source in FTP.

Commercial Servers

If you cannot run your own server, thousands of companies are available and willing to lease you one: [Web Hosting http://directory.google.com/Top/Computers/Internet/Web_Design_and_Development/Hosting/]

Clients

See: FTP Clients

Open Directory Project - More FTP Software


FTP Transfer Modes

FTP uses both ASCII and binary transfer modes. Later implimentations like SSH make this distinction automatically.

ASCII vs. Binary Mode in FTP

Sending files in ASCII format is around 12% faster but should be only be used on text files. Text uses only 7 of the 8 bits in a byte, while binary data uses all 8. If a file is already known to be ASCII, every 8th bit is implied on the destination system and need not be transmitted. Setting binary mode in FTP alerts both the sender and receiver that all 8 bits need to be transmitted. Thus, binary mode can be safely used for all files, while ASCII mode should only be used for text files.

A thorough explanation can be found here.

Passive Mode FTP

Created to handle issues with Firewalls, Passive Mode FTP was added to conventional FTP to handle port commands differently than Active Mode and trick Firewalls so they would not block transmission. [ More info]...

Common UNIX command-line FTP uses

When using a UNIX Terminal, such as in Mac OS X or Linux, FTP operations can be run on the command line. Using the command line takes up very little system memory and resources.

At the prompt, type in ftp sitename

#ftp www.ftpsite.com

And enter your username and password.

Some FTP servers use UNIX commands (ls, rm, rmdir), others DOS (dir, del) but all will use "cd" for change-directories.

Nearly all transfers will need to be in Binary mode, which won't be the default mode. Type:

#ftpsite>bin

And turn off prompting for long lists of files.

#ftpsite>prompt

Then find the directory with the given information you need and enter mget:

#ftpsite>mget *.avi

And the server will download all avi files.

Once started, they can be sent into the background of a given terminal:

#ftpsite>bg %1

... so that another FTP transfer can be started. If you have multiple jobs running, they will be %1, %2, and %3 respectively.

To check on the status and whether a given job has finished type fg (for "foreground"):

#<ftpsite>fg %1

To see the various different backgrounded programs workin in memory type:

#<ftpsite>jobs


More information available:

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