I developed this PHP function for a project I’m working on. I’m posting it here in case I need it again, or in case you find it handy.

#Input text files must contain one item per line
function print_menu($txtfile_or_files){
	$args = func_get_args();
	$num_args = func_num_args();
	$input = array();

	for($i = 0; $i < $num_args; $i++){
		// get contents of each text file specified
		$lines = file($args[$i]); 

		// get each line from each file an add to array
		for($j = 0; $j < count($lines); $j++){
			array_push($input,$lines[$j]);
		}
	}
	// sort alphabetically
	sort($input,SORT_STRING);		

	for($i = 0; $i < count($input); $i++){
		$value = str_replace(' ','_',strtolower(trim($input[$i])));
		echo '<option value="'.$value.'">'.trim($input[$i])."</option>\n";
	}
}

Configuration and use

The variable $txtfile_or_files should be a comma-separated list of paths to plain text files. This function accepts multiple arguments, in case you want to string multiple files into one menu.

Each text file should contain one item per line. For example:

Red
Blue
Orange
Green

Add another line or two of code if you need to indicate whether the form field value has already been selected.