的fwrite(); 在特定行之前和之后

I'm now using the function fwrite(); in PHP. But i want to locate my new things after a specific rule.

This wil be the output.

<?xml version="1.0" encoding="utf-8" ?> 
<logs>
    <log type="text">the new log</log>
    <log type="text>the old log</log>
    <log type="login">some other log.</log>
</logs>

How can i get the new log in the new log and not on the end. I only can find something like file_get_contents and then str_replace. But that seems really not efficient.

My php Code:

$file = $this->path.'logs.xml';
    // Open our file. And Create file if it doesn't exsist
    $fopen = fopen($file, "w+");

    // Looks if file is empty.
    if(filesize($file) == 0) {

        /*
         * Put your data in XML data.
         */
        $xmlData = "<?xml version=\"1.0\" encoding=\"utf-8\" ?> 
";
        $xmlData .= "<logs> 
";
            $xmlData .= "\t<log type=\"".$data[0]."\">
";
                $xmlData .= "\t\t<author>".$data[1]."</author>
";
                $xmlData .= "\t\t<action>".$data[2]."</action>
";
                $xmlData .= "\t\t<result>".$data[3]."</result>
";
                $xmlData .= "\t\t<note>".$data[4]."</note>
";
            $xmlData .- "\t</log>
";
        $xmlData .= "</logs>";

    } else {



    }

    if(is_writeable($file)) {

        fwrite($fopen, $xmlData);
        return true;

    }
    return false;
    fclose($fopen);

Sincerely thank you.

Well, you're lucky your data is in XML. PHP has got a bunch of easy to use libraries (extensions) that deal with XML data. For example SimpleXML or the more capable DOM (both extension are enabled by default).

<?php
    $filename = $this->path.'logs.xml';

    if (!file_exists($filename)) {
       // Here's your code from above, although it would be easier to use
       // the libraries here, as well
    } else {
       $logs = simplexml_load_file($filename);
       // See if there's a "text" log element
       $txtlog = $logs->xpath('./log[@type = "text"]');
       ...
    }

You could use the array_splice method. This way you can insert a new element in an array at any position.

$file = $this->path.'logs.xml';

$content = file($file); //is array with all lines as elements.

/*
0: <?xml version="1.0" encoding="utf-8" ?> 
1: <logs>
2:    <log type="text>the old log</log>
3:    <log type="login">some other log.</log>
4: </logs>
*/

//insert the new line at position 2
array_splice( $content, 2, 0, '    <log type="text">the new log</log>' );

/*
0: <?xml version="1.0" encoding="utf-8" ?> 
1: <logs>
2:    <log type="text">the new log</log>
3:    <log type="text>the old log</log>
4:    <log type="login">some other log.</log>
5: </logs>
*/

$fopen = fopen($file, "w+");
fwrite($fopen, implode("
", $content);
fclose($fopen);