[WordPress] How to remove extraneous characters from the end of a line before preparing to write it to a file.

1-generating-a-record.php

<?php

/**
 * Note that in a production environment, much of this could would
 * reside in several separate functions. It's shown here in one gist
 * to illustrate the point more succinctly.
 */

/**
 * Setup the WP Query arguments to retrieve all published
 * posts of the 'acme_post_type' sorted by ascending
 * title.
 */
$args = array(
	'post_type'      =>  'acme_post_type',
	'post_status'    =>  'publish',
	'orderby'        =>  'title',
	'order'          =>  'asc',
	'posts_per_page' =>  -1
);
$custom_posts = new WP_Query( $args );

/**
 * If there are posts, then loop through them creating
 * a line to add to the CSV to write to the file.
 */
$csv_line = '';
if ( $custom_posts->have_posts() ) {
  
  while ( $custom_posts->have_posts() ) {
    
    $custom_posts->the_post();
    
    // Grab the post title and a piece of associated meta data
    $title = get_the_title();
    $meta_data = get_post_meta( get_the_ID(), 'acme_meta_data', true );
    
    // Append the content to the line to be written to the file
    $csv_line = '"' . $title . '","' . $meta_data . '","' . "\"\r\n";
    
    // Assume that we already have a file handle for writing the file
    fwrite( $file_handle, $csv_line );
    
  }
  
}

2-removing-extraneous-characters.php

<?php

while ( $custom_posts->have_posts() ) {
  
  /* Snip for redundancy */
  
  // Append the content to the line to be written to the file
  $csv_line = '"' . $title . '","' . $meta_data . '","' . "\"\r\n";
  
  // Replace any "", with , and replace any trailing "" with an empty space
  $csv_line = str_ireplace( ',""', '', str_ireplace( '"",', ',', $csv_line ) );
  
  // Assume that we already have a file handle for writing the file
  fwrite( $file_handle, $csv_line );
  
}