How to get the FTP error when using PHP

Based on @Sascha Schmidt answer, you could do something like this:

if (ftp_rename($conn_id, $old_file, $new_file)) {
 echo "successfully renamed $old_file to $new_file\n";
} else {
 echo "There was a problem while renaming $old_file to $new_file\n";
 print_r( error_get_last() ); // ADDED THIS LINE
}

print_r will display the contents of the error_get_last() array so you can pinpoint the error.

I'm doing something like:

$trackErrors = ini_get('track_errors');
ini_set('track_errors', 1);
if (!@ftp_put($my_ftp_conn_id, $tmpRemoteFileName, $localFileName, FTP_BINARY)) {
   // error message is now in $php_errormsg
   $msg = $php_errormsg;
   ini_set('track_errors', $trackErrors);
   throw new Exception($msg);
}
ini_set('track_errors', $trackErrors);

EDIT:

Note that $php_errormsg is deprecated as of PHP 7.

Use error_get_last() instead.

See answer by @Sascha Schmidt

Looking at the FTP API here:

http://us.php.net/manual/en/function.ftp-rename.php

There doesn't seem to be any way to get anything but true or false.

However, you could use ftp_raw to send a raw RENAME command, and then parse the returned message.

You could use error_get_last() if return value is false.