How to delete content from php files

In PHP, file operations are an important topic. Deleting the contents of a file is a frequently encountered need. This article will introduce several methods to delete the contents of PHP files.

1. Using file_put_contents()

The file_put_contents() function has a special usage to choose to clear the file contents. When the first parameter is the name of the file to be deleted, and the second parameter is an empty string, the file contents can be cleared.

$file = 'test.txt';
file_put_contents($file, '');  // 清空文件内容

2. Using fopen() and fwrite()

Another method is to use the fopen() and fwrite() functions to open a file and use the fwrite() function Write an empty string to the file to clear its contents.

$file = 'test.txt';
$handle = fopen($file, 'w');
fwrite($handle, '');   // 清空文件内容
fclose($handle);

3. Use file_get_contents() and file_put_contents()

Another method is to use the file_get_contents() function to read the contents of the current file, and then use the file_put_contents() function to overwrite it original file, which will cause the file to be emptied. Here is an example:

$file = 'test.txt';
$contents = '';
file_put_contents($file, $contents);  // 清空文件内容

4. Using truncate()

The last method is to use the truncate() function. This function is used to truncate the file. Set the file size to 0, which deletes its contents. Here's an example:

$file = 'test.txt';
$handle = fopen($file, 'w');
ftruncate($handle, 0);   // 清空文件内容
fclose($handle);

Summary

This article explains four ways to delete content from PHP files. The file_put_contents() and fwrite() functions are the simplest and most straightforward methods. The file_get_contents() and truncate() functions require more code, but are good choices and have different use cases. Whichever method you choose, you should stay safe and careful to make sure you don't accidentally delete the files you need.

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