Search for string followed by whitespace

At the moment, I'm doing this: $start = stripos ($body, "<a ", $loc); You'll note the space after the '<a'. But I really need to search in $body for '<a' followed by any whitespace char, at least one, starting at the $loc'th character, and returning the location of the string in $start. I had a look at the PCRE and POSIX regexp functions to no avail. Is there a slick way of doing this with one function call or should I just search for '<a' and brute-force check that the next char is ' ' or '\t' or '\n'? Thanks, -- Cheers -- Tim