WordPress Search & Replace in posts

wp-search-replace-function.php

<?php

/**
*
* Search & Replace in WordPress posts
*
*/


function mytheme_go_replace(){

	// sidebar :
	mytheme_replace_content(
		$my_postid 		= 12,
		$toreplace 		= "REPLACEME",
		$replabeby 		= "REPLACED"
	);

	// footer :
	mytheme_replace_content(
		$postid 		  = 22,
		$toreplace 		= "REPLACEME",
		$replabeby 		= "REPLACED"
	);

}


function mytheme_replace_content($postid, $toreplace, $replabeby){

	$content 		  = get_post_field('post_content', $postid);
	$newcontent 	= str_replace($toreplace, $replabeby,$content);

	$blogname 		= get_bloginfo('name');

	
		if (strpos($content, $toreplace) !== false) {

			$mypost = array(
		      'ID'           => $postid,
		      'post_content' => $newcontent
		  	);
			wp_update_post( $mypost );

		}
	

}
// add_action('wp_head', 'mytheme_go_replace');