How can headers already sent errors be avoided in PHP scripts when trying to set header information for file downloads?

Headers already sent errors in PHP scripts when trying to set header information for file downloads can be avoided by ensuring that no output is sent to the browser before setting the headers. This can be achieved by moving the header setting code to the beginning of the script before any other output is generated. 

<?php
// Set headers for file download
header('Content-Type: application/octet-stream');
header('Content-Disposition: attachment; filename="example.txt"');

// Output file content
echo "This is the content of the file.";
?>

Keywords

output buffering ob_start ob_end_flush header Content-Disposition

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