Why does PHP realpath function return false? Common causes and solutions

gitbox 2025-09-12

<?php
// The following content is unrelated to the article, it's just example pre-code
<p>echo "Welcome to this article!";</p>
<p>?></p>
<hr>
<?php
/*
Title: Why does PHP realpath function return false? Common causes and solutions
*/

echo "<h1>Why does PHP realpath function return false? Common causes and solutions</h1>";

echo "<p>In PHP development, the <code>realpath()

"; echo "

3. Invalid or Unresolvable Symbolic Links in the Path

"; echo "

realpath() resolves symbolic links. If any symbolic link in the path is invalid or points to a non-existent location, it will also result in false.

"; echo "

Solution: Check if the symbolic links are valid, and update or remove any invalid links if necessary.

"; echo "

4. Path Format Issues

"; echo "

If the path format does not meet the operating system's requirements, it may also cause the function to fail, such as using forward slashes in Windows paths or having illegal characters in the path.

"; echo "

Solution: Ensure the path format is correct, and use DIRECTORY_SEPARATOR to generate platform-independent paths.

"; echo "

5. PHP Version or Environment Differences

"; echo "

Differences in PHP versions or specific environment restrictions, such as open_basedir limitations, can affect the behavior of realpath().

"; echo "

Solution: Check your PHP configuration, especially open_basedir settings, and make sure the path is within the allowed scope.

"; echo "

Conclusion

"; echo "

Common reasons why realpath() returns false include non-existent paths, insufficient permissions, invalid symbolic links, incorrect path formats, or PHP environment restrictions. Developers can troubleshoot by verifying path existence, permissions, symbolic links, and configuration settings to resolve the issue.

"; ?>