How to replace fields from file_A with fields from file_B

Question

I have a file like:

{&structure_name.field, sizeof(structure_name.field),
 &structure_name.field, sizeof(structure_name.field), TODO },
{&structure_name.field, sizeof(structure_name.field),
 &structure_name.field, sizeof(structure_name.field), TODO },
{&structure_name.field, sizeof(structure_name.field),
 &structure_name.field, sizeof(structure_name.field), TODO },   

and another file that has 3 records with two fields on each line:

123 fun1   
456 sum_fun
789 multi_fun

I want to write a quick command which will give me something like below:

{&structure_name.123, sizeof(structure_name.123),
 &structure_name.123, sizeof(structure_name.123), fun1 },
{&structure_name.456, sizeof(structure_name.456),
 &structure_name.456, sizeof(structure_name.456), sum_fun },
{&structure_name.789, sizeof(structure_name.789),
 &structure_name.789, sizeof(structure_name.789), multi_fun },   

Answer 1

You could try something like this:

awk 'NR==FNR { a[2*NR] = $1; a[2*NR-1] = $1; b[2*NR] = $2; b[2*NR-1] = $2; next; }
     { gsub(/field/, a[FNR]); gsub(/TODO/, b[FNR]); print; }' patterns input