[PHP] Using fopen and fread with PHP

[litewarez]

In PHP we have several connectivity functions that allow us to open connections to local and non-local streams such as files and http requests

The first version im going to show you is a local file, where you dont need to send any information such as headers to get data, but mealy open a stream and read.

Heres a brief desctiption if what the functions are used for.

fopen:
this is is usually know as file-open and is used to open a stream and store the connection data in the memory as a resource. this will return a resource witch will be used on conjunction with other parameters

fread:
This is used to read a defined amount of bytes from a stream, for example a line or 256 byts, this takes the resource that is returned by the above

fclose:
This is used to close a stream and free its memory blocks, this will unset the resource variable aswell.

fputs:
This is used to send data to a resource to be added to the content, this also takes the resource generated by the fopen command.


Ok so lets get started with a basic example and then talk about what's going on

$resource = fopen('/temp/sample.ext','rb');
$data = array();

while(false != ($contents = fread($resource,128)))
{
     $data[] = $contents;
} 

Explanation:

• Creating a file pointer / resource
• creating a data array to store data
• reading using fread for a lengh of 128 untill theres no more contents.
• Storing the contents into the data array

Note: in Fopen the second parameter is the read bod witch r = read and b = binary, we have to use b on windows systems.

Each block in the data array will contain 128 bytes, this is basically splitting the read contents into chunks.

Heres another example of reading a webpage:

$resource = fopen('http://google.com','r');
$data = '';
while(false != ($contents = fread($resource,256)))
{
     $data .= $contents;
} 

This example is the same as above, bar the address and read mode..
as were connection via the http:// socket fopen knows that its connecting externally. heres some more protocols you can use

• ftp://
• https://
• data://
• php://
• ssh2.shell://
• compress.zlib://
• compress.bzip2://
• ogg://

The list is much greater and is really scalable.

Ok so lets show an example of reading and putting in FTP://.

$ftp_login_url = 'ftp://user:pass@hostname.com/';
$resource = fopen($ftp_login_url);
ftp_pasv($resource, true);

ftp_fput($resource, 'wordpress.zip', fopen('wordpress.zip'), FTP_ASCII);
fclose($resource); 

AS you can see from the above example were connecting to the ftp socket via fopen and passing the credentials for the login via the userass section of the url. then we proceed to set the ftp mode as "pasive"..

The next part is putting a resource/fopen(ed)-file onto the server with a fillename and transfer mode.

Hope you enjoyed this

litewarez Reviewed by litewarez on 4th Jul 2010. [PHP] Using fopen and fread with PHP In PHP we have several connectivity functions that allow us to open connections to local and non-local streams such as files and http requests The first version im going to show you is a local file, where you dont need to send any information such as headers to get data, but mealy open a stream and read. Heres a brief desctiption if what the functions are used for. fopen: this is is usually know as file-open and is used to open a stream and store the connection data in the memory as a Rating: 5