PHP open a php file and replace content

Your problem:

If you use file_get_contents you don't pass a file handle but the path to the file as a string.

While

$fh = fopen("c/".$file."/underbaba.php", 'w');

without writing to the file with fwrite will result in simply erasing the file. Also the file should be fclosed before the script ends.

The solution:

Simply Use file_get_contents to read the file then file_put_contents to write.

$contents = file_get_contents( $full_path_to_file );
$contents = str_replace( 'error":4,', 'error":0,', $contents );
file_put_contents( $full_path_to_file, $contents );

You get a very little overhead versus using a sequence of fopen, fread, fseek, fwrite, fclose because the file is opened and closed twice but I don't think this is an issue.

Worth mentioning that file_get_contents will read all the whole file at once and store it into memory so this solution is feasable only with files with a reasonable size.

You may add error handling easily:

$contents = file_get_contents( $full_path_to_file );
if( $contents === false )
{
    // an error occurred reading
}

$contents = str_replace( 'error":4,', 'error":0,', $contents );

$bytes_written = file_put_contents( $full_path_to_file, $contents );
if( $bytes_written !== strlen( $contents ) )
{
    // an error occurred writing
}

As you're operating on a set of files setup a for / foreach loop setting $full_path_to_file properly at each iteration.

For your reference:

file_get_contents

file_put_contents

You need to open your file in append mode use mode a+ or r+ for this

Please check the below link for help https://www.w3schools.com/php/php_file_open.asp

If that is all you are doing, then yes you are emptying your file. According to the manual:

'w' Open for writing only; place the file pointer at the beginning of the file and truncate the file to zero length. If the file does not exist, attempt to create it.

Are you writing the string you have modified back to the file somewhere as well?

The most efficient and understandable workaround to manage file contents with methods as file_put_contents() for me is wrapped in the function below.

Worked great for me and seemed to be much faster than the previous function I used, which included fopen(), file_put_contents() and many more resource consuming functions. This function also works well with large files of code.

function replace_contents( $path, $string, $replace ) {
    $str_to_arr = preg_split( "#/#", $path );
    $file_name  = array_pop( $str_to_arr );
    $dir        = implode( '/',$str_to_arr );
    
    if ( is_file($path) ) {
        return exec(
            'cd ' . $dir . PHP_EOL .
            "sed -i 's/" . $string . "/" . $replace . "/g' " . $file_name
        );
    }
}

• $str_to_arr - String to array conversion (including the file)
• $file_name - Get the last index of the above array (the actual file name)
• $dir - Get the the actual path (without the file name) so

And finally use exec() to perform a simple Unix command which replaces the inner file content located in the path passed to the function params.

sed 's/unix/linux/g' geekfile.txt