Searches for the specified pattern in a string
(vl-string-search pattern string [start-pos])
A string containing the pattern to be searched for.
The string to be searched for pattern.
An integer identifying the starting position of the search; 0 if omitted.
nil if the pattern is not found; the first character of the string is position 0.An integer representing the position in the string where the specified pattern was found; otherwise
_$ (vl-string-search "foo" "pfooyey on you")
_$ (vl-string-search "who" "pfooyey on you")
_$ (vl-string-search "foo" "fooey-more-fooey" 1)