Explanation of PHP fopen Function Usage Example

The php fopen () function is used to open a file or URL.

php fopen () Function Syntax

Function: Open file or URL.

Syntax:

fopen(filename,mode,include_path,context)

Parameters:

filename required. Specify the file to open or URL.

mode required. Specify the type of access required to the file/stream.

include_path is optional. If you also need to retrieve files in include_path, you can set this parameter to 1 or TRUE.

context is optional. Specifies the environment for file handles. Context is a set of options that can modify the behavior of a stream.

Explanation: fopen () binds the name resource specified by filename to a stream. If filename is in the format of "scheme://...", it is treated as an URL, and PHP will search for a protocol handler (also known as an encapsulation protocol) to handle this pattern.

If the protocol has not registered an encapsulation protocol, PHP will send a message to help check for potential problems in the script and continue with filename as a normal file name.

If PHP considers that filename specifies a local file, it attempts to open a stream on that file. The file must be accessible by PHP, so you need to confirm that file access permissions allow that access. If Safe Mode or open_basedir is activated, the restriction of Step 1 is applied.

If PHP considers that filename specifies a registered protocol and that protocol is registered as a network URL, PHP checks and confirms that allow_url_fopen is activated. If it is turned off, PHP will issue a warning and the call to fopen will fail.

Example of php fopen () Function

<?php
$file = fopen("./test.txt","r");
?>

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