vnlog 1.33 released

Prints out the existing columns, and exits. I've been low-level wanting this for years, but never acutely-enough to actually write it. Today I finally did it.

Defines an absolute-value abs() function in the default awk mode. I've been low-level wanting this for years as well. Previously I'd use --perl just to get abs(), or I'd explicitly define it: =–sub 'abs(x) {return x>0?x:-x;}'=. Typing all that out was becoming tiresome, and now I don't need to anymore.

Theses add BEGIN and END clauses. They're useful to, for instance, use a perl module in BEGIN, or to print out some final output in END. Previously you'd add these inside the --eval block, but that was awkward because BEGIN and END would then appear inside the while(<>) { } loop. And there was no clear was to do it in the normal -p mode (no --eval).

Clearly these are all minor, since the toolkit is now mature. It does everything I want it to, that doesn't require lots of work to implement. The big missing features that I want would patch the underlying GNU coreutils instead of vnlog:

• The sort tool can select different sorting modes, but join works only with alphanumeric sorting. join should have similarly selectable sorting modes. In the vnlog wrappe I can currently do something like vnl-join --vnl-sort n. This would pre-sort the input alphanumerically, and then post-sort it numerically. That is slow for big datasets. If join could handle numerically-sorted data directly, neither the pre- or post-sorts would be needed
• When joining on a numerical field, join should be able to do some sort of interpolation when given fields that don't match exactly.

Both of these probably wouldn't take a ton of work to implement, and I'll look into it someday.