How can file permissions (chmod) affect the success of file uploads via FTP in PHP?

File permissions can affect the success of file uploads via FTP in PHP if the directory where the files are being uploaded does not have the correct permissions set. If the directory does not have write permissions for the user that PHP is running as, the file upload will fail. To solve this issue, you need to ensure that the directory has the correct permissions set to allow the PHP process to write files to it.

// Set the correct permissions for the upload directory
chmod('/path/to/upload/directory', 0777);