如何在任何单词之前将一些信息写入文件末尾？

Question

I want write information to end of file before last word. How can I do that? My code:

$fp=fopen("sitemap.xml","a");
fwrite($fp, "
" . "My information");
fclose($fp);

Answer 1

Before the last word?
Seek to the end of the file, backtrack until first whitespace character, save all data from current point to EOF, insert your data, insert saved data

Update #1

Change the mode of your fopen to r+ as a will always write @ EOF