first impression aya PHP FTP learning (1)

By Vikram Vaswani
Melonfire
November 07, 2000
We are a group of loyal fans of PHP. We use it for various reasons - WEB site development, drawing, database connection, etc. - we find that it is very friendly and powerful. And easy to use...
You may have seen how PHP is used to create GIF and JPEG images, dynamically obtain information from databases, etc., but this is just the tip of the iceberg---the latest version of PHP has powerful File transfer function.
In this tutorial, I will show you how FTP transfers files through HTTP and FTP connections. There will also be some simple program codes. Follow me!
First of all, you should know that PHP transfers files through HTTP and FTP connections. Uploading files through HTTP has already appeared in PHP3, and now, the new FTP function has appeared in the new PHP version!
Before you start, you need to make sure that your PHP supports FTP. You can check it through the following code:
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phpinfo();
?>
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Check the output , there is an "Additional Modules" area, which lists the modules supported by your PHP; if you do not find the FTP module, you'd better reinstall PHP and add FTP support!
Let’s first take a look at how a typical FTP task is completed!
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$ ftp ftp.server.com
Connected to ftp.server.com
220 server .com FTP server ready.
Name (server:john): john
331 Password required for john.
Password:
230 User john logged in.
Remote system type is UNIX.
Using binary mode to transfer files.
ftp> ls
200 PORT command successful.
150 Opening ASCII mode data connection for /bin/ls.
drwxr-xr-x 5 john users 3072 Nov 2 11:03 .
drwxr-xr-x 88 root root 2048 Nov 1 23: 26..
drwxr--r-- 2 john users 1024 Oct 5 13:26 bin
drwx--x--x 8 john users 1024 Nov 2 10:59 public_html
drwxr--r-- 4 jo hn users 1024 Nov 2 11:26 tmp
-rw-r--r-- 1 john users 2941465 Oct 9 17:21 data.zip
226 Transfer complete.
ftp> bin
200 Type set to I.
ftp> get data.zip
local: data.zip remote: data.zip
200 PORT command successful.
150 Opening BINARY mode data connection for data.zip(2941465 bytes).
226 Transfer complete.
ftp> bye
221 Goodbye.
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You can see that the process is obviously divided into several stages: connection (establishing a connection with the FTP server), Verification (determining whether the user has the authority to enter the system), transmission (this includes listing directories, uploading or downloading files), and canceling connections.
Steps to use PHP for FTP
Establishing a PHP FTP connection must follow the following basic steps: Open a connection - Issue authentication information - Use PHP functions to manipulate directories and transfer files.
The following specific implementation:
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// Connect to FTP server
$conn = ftp_connect("ftp.server.com");
// Use username and password to log in
ftp_login($conn, "john", "doe");
// Get the remote system type
ftp_systype($conn);
// List files
$filelist = ftp_nlist($conn, ".");
// Download files
ftp_get($conn, "data.zip", "data.zip", FTP_BINARY);
// Close the connection
ftp_quit($conn);
?>
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Let's do it step by step:
In order to initialize an FTP connection, PHP provides the ftp_connect() function, which uses the host name and port as parameters. In the above example, the host name is "ftp.server.com"; if the port is not specified, PHP will use "21" as the default port to establish the connection.
After the connection is successful, ftp_connect() returns a handle; this handle will be used by the FTP function used later.
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// connect to FTP server
$conn = ftp_connect("ftp .server.com");
?>
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Once the connection is established, use ftp_login( ) sends a username and user password.You can see that the function ftp_login() uses the handle passed by the ftp_connect() function to determine that the username and password can be submitted to the correct server.
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// log in with username and password
ftp_login($conn, "john", "doe");
?>
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At this time, you You can do what you want to do, which will be explained in the next part:
After you finish doing what you want to do, be sure to remember to use the ftp_quit() function to close your FTP connection
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// close connection
ftp_quit($conn);
?>

The above introduces the FTP learning of first impression aya PHP (1), including the content of first impression aya. I hope it will be helpful to friends who are interested in PHP tutorials.