|
What Is FTP And How It Works?
|
By Vladimir Ghetau
[Hits: 9021]
|
|
FTP is a method to manage files over the Internet or anetwork: meet the File TransferProtocol!
People are generally using the FTP for transfering the filesuploaded on their web hosting server. We already talking aboutfiles... trasfer, and most important... protocols.
A protocol is a method which informs your computer about theconnection to a server or client (in a nut shell, tells thebrowser how to get the file, how to read the informations aboutit, etc).
The FTP is a common process used in file trasfers fromone computer to another: one computer is the server and theother one is being called - the client (because it connects tothe server).
A server is uploading when sending files, and the client isdownloading them. These are commonly used terms and I believeyou have heard about them before.
To access a FTP server you need an internet or networkconnection, a FTP address, a username and a password.
The FTP address of the server is the main thing you must knowbefore accessing a server. Here is an example: a friend of mineput some files on his computer and gave me the adress whichlooks like this: ftp.myfriendsdomain.com
To access this address, i can use my browser (e.g. Firefox,Internet Explorer, etc), or a FTP Client (a software forconnecting to FTP servers).
It's possible the server to be password protected, or I willconnect anonymously using my email address as a password.
Connecting anonymously?
That's right! If the server is granting acess to everybody, youwill connect anonymously - using anonymous word as username andyour email address as password. But this happens only when youare allowed to connect anonymously.
In many cases privacy is king. For this reason, the anonymousconnection mode is disabled. You will need a username andpassword to establish a connection to that server. The method isused for protecting different areas on the server.
Clients and browsers?
There is a big difference from connecting to a FTP server usinga browser or a client. In most cases the browser will allow toconnect and download files from a server.
On the other hand, if you are using a FTP client you can:download, upload, delete files, etc.
FTP vs. HTTP
Accessing a server using the HTTP (Hyper Text TrasferProtocol) is commonly used for websites. If you will accesswww.cnn.comwith your browser, you got yourself a quick HTTP connection.
Let me show you two major differences between FTP and HTTP:
1) When connecting to a FTP server you are using a FILE server(that means you can't see anything but files there), but if youconnect to a HTTP server you access a WEB server, which meansyou can load web pages into a browser.
2) Using a FTP connection you can download and upload files tothe server, but when you use the HTTP connection you can onlydownload content from the Internet for viewing, is a "read only"method.
Another thing you can do with the FTP method is to change modeof the files. Why? Because you might use certain files that needdifferent permissions.
For example I have a small web application which stores yourname and email address inside a file on the server. If that fileis write protected, I can't store any information. I need tochange it's writing permission. This step is also calledchmod-ing a file.
What is CHMOD?
The chmod command is used to change permissions of a fileusing the File Trasfer Protocol.
After you've uploaded something on a server you might want toset up the file permissions. For example: the owner can changethe file's content, but any visitor comming here can only readit.
This is done using 3 simple commands: write, read, execute.
Every command can be assigned (in the same time or dispersed)for owner, groups and anyone else.
Sometimes the chmod commands are hard to use and understand, butnow it's easier, thanks to the three digit numbers!
Here are the most used commands for chmod-ing a file:
CHMOD 644 The file can be read by: owner, groups andeveryone else, but can't be changed, or executed but otherpeople excepting the owner.
CHMOD 700 The file can be read, written and excuted bythe owner (user). The groups and everyone else can't read, writeor execute it.
CHMOD 755 The owner, the group and everyone else can readand execute the file, but only the owner can write it. (this isa very common option for chmoding a file because allows theexecution of a file - it's valuable for web applications).
CHMOD 777 Full access to everyone for reading, executingor writing the data.
Fact: FTP is used mostly for uploading files to a webhosting server! Webmasters are using this procedure to putwebsites online for their visitors.
Free FTP Clients (some of them are free only for personaluse):
-WS_FTP
-AutoFTP
-FTP Explorer
-FTP Works
-SmartFTP
Best wishes,
Vladimir Ghetau
|
|
|
|
