match-data

match-data is a built-in function in `C source code'.

(match-data &optional INTEGERS REUSE RESEAT)

Return a list containing all info on what the last search matched.
Element 2N is `(match-beginning N)'; element 2N + 1 is `(match-end N)'.
All the elements are markers or nil (nil if the Nth pair didn't match)
if the last match was on a buffer; integers or nil if a string was matched.
Use `set-match-data' to reinstate the data in this list.

If INTEGERS (the optional first argument) is non-nil, always use
integers (rather than markers) to represent buffer positions. In
this case, and if the last match was in a buffer, the buffer will get
stored as one additional element at the end of the list.

If REUSE is a list, reuse it as part of the value. If REUSE is long
enough to hold all the values, and if INTEGERS is non-nil, no consing
is done.

If optional third arg RESEAT is non-nil, any previous markers on the
REUSE list will be modified to point to nowhere.

Return value is undefined if the last search failed.