[help-recutils] How to do some selection

[Fabrice DURAND]

Hello

First of all, "bravo" for this tool , i like it.
I would like to do some selections:

I have one recfile RTL.rec with fields

Date, Auteur, Titre, Section

How could i select records with field Section not equal to null ?
How could i select records with field Auteur contains a string ?
   as an example 
   i would like to have all record where field Auteur contains string "cold"

How could i count  number of record with field Auteur equal to "U2" ?

Thanks for any answer

Regards