How to escape percent symbols in the format parameter string of sprintf()

Question

How do I add the SQL wildcard characters to this:

 sprintf("SELECT robot FROM robots WHERE robot LIKE '%s'",strtolower($user_agent));

as

 sprintf("SELECT robot FROM robots WHERE robot LIKE '%%s%'",strtolower($user_agent));

I need the %s placeholder to be wrapped in literal % characters without disrupting the placeholder.

Answer 1

A literal % is specifed as %%, so you want "... LIKE '%%%s%%'"