Concatenate C macro definition string to literal strings

Question

Let the first row be:

#define TAG_LEN 32

Now, I need to concatenate it with a literal string constant; something like that:

puts("Blah" [insert your answer] TAG_LEN); // I need "Blah32".

Answer 1

#define STR_NOEXPAND(tokens) # tokens
#define STR(tokens) STR_NOEXPAND(tokens)
puts("Blah" STR(TAG_LEN));