如何在没有并发问题的情况下替换php中文件的内容

Question

I want to append an HTML attribute id="active" for a link of left.php

left.php should have only one link with id="active"

The below code is actually working as per my requirement, but after a while the content of left.php is totally missing due to concurrency issues.

How can I resolve the issue?

I think we can have a java script solution for this to handle at client side. Please let me know the best solution with example.

Thank you all.

<?php 
$searchF1  = ' id="active"';
$replaceW1 = '';
$searchF = basename(__FILE__).'"';
$replaceW = $searchF.' id="active"';

$myfile = fopen( 'left.php', 'rt' );
flock( $myfile, LOCK_SH );
$file = file_get_contents( 'left.php' );
fclose( $myfile );

$file = str_replace( $searchF1, $replaceW1, $file );
$file = str_replace( $searchF, $replaceW, $file );

file_put_contents('left.php', $file);

include('left.php');
?>  

Answer 1

I think you are trying to set the link of the current page as active. In this case you are doing it wrong. All the logic must be inside the left.php file. You can do it like this:

$pages = array(
    'firstPage.php'  => 'First Page',
    'secondPage.php' => 'Second Page',
    'thirdPage.php'  => 'Third Page',
);

$currentParsedUrl = parse_url("http://$_SERVER[SERVER_NAME]$_SERVER[REQUEST_URI]");
$currentPath = ltrim($currentParsedUrl['path'], '/');

foreach ($pages as $path => $name) {
    echo '<a href="/' . $path . '"'; 
    echo $currentPath == $path ? ' id="active"' : '';
    echo '>' . $name . '</a>';
}

Now all you have to do is to include the left.php file wherever you want to display those links.