Question

I’ve written a simple config file parser in yacc, which processes files like this:

asdf=50
foobar=42

I.e. word=number.

My question is, how do I integrate this into my program? I would ultimately like to have the processed values stored in some internal data structure that I can access later as I please. Every yacc example I have seen simply printf()s the value out to stdout, but that seems kind of useless in an actual program.

Answer 1

You can replace those printf’s by code that inserts the data into a data structure of your own. Something like this:

rule: TOKEN1 TOKEN2 TOKEN3 
      {
          add_data(your_data, $1, $2, $3);
      };

where add_data is a function that adds the data contained in $1, $2, and $3 to a custom data structure contained in the variable your_data.

I’m afraid your_data has to be global. I dug in some old yacc projects I have and in other stackoverflow questions like this and I haven’t found another way of doing it. If someone knows of a better way, please comment.

If you post your code I can try to help you with specifics.