multi-wildcard pattern rules of GNU Make

Question

I want to write something like regex:

SRC:=\"a.dat.1 a.dat.2\"    
$(SRC): %.dat.%: (\\\\1).rlt.(\\\\2)    
      dat2rlt $^ $@

so that

Answer 1

For the limited example you gave, you can use a pattern with one %.

SRC := a.dat.1 a.dat.2
${SRC}: a.dat.%: a.rlt.%    
      dat2rlt $^ $@

1. $* in the recipe will expand to whatever the % matched.
2. Note that the "s around your original macro are definitely wrong.
3. Have a look at .SECONDEXPANSION in the manual for more complicated stuff (or over here).