GNU Emacs Lisp Reference Manual

30.6.3: Accessing the Entire Match Data

The functions match-data and set-match-data read or write the entire match data, all at once.

Function: match-data

This function returns a newly constructed list containing all the information on what text the last search matched. Element zero is the position of the beginning of the match for the whole expression; element one is the position of the end of the match for the expression. The next two elements are the positions of the beginning and end of the match for the first subexpression, and so on. In general, element number 2n corresponds to (match-beginning n); and element number 2n + 1 corresponds to (match-end n).

All the elements are markers or nil if matching was done on a buffer, and all are integers or nil if matching was done on a string with string-match. (In Emacs 18 and earlier versions, markers were used even for matching on a string, except in the case of the integer 0.)

As always, there must be no possibility of intervening searches between the call to a search function and the call to match-data that is intended to access the match data for that search.

(match-data)
     =>  (#
          #
          #
          #)

Function: set-match-data match-list

This function sets the match data from the elements of match-list, which should be a list that was the value of a previous call to match-data.

If match-list refers to a buffer that doesn't exist, you don't get an error; that sets the match data in a meaningless but harmless way.

store-match-data is an alias for set-match-data.