Temporary files don't bite, so just use them.
Archive of posts tagged awk
Joining files with awk
Join lines from files based on keys
Awk pitfall: string concatenation
This is a bit of a dark corner of awk. This beast is string concatenation. There is a classical example in the awk FAQ number 28: $ awk 'BEGIN { print 6 " " -22 }' 6-22 Where did the space go? First, " " -22 is evaluated, in numeric context, yielding 0-22 = -22. […]
Smart ranges in awk, part two
Another variation on the theme