[Feature] using a regex for RS [POSIX awk] no (undefined) [GNU awk 3.1.6] yes, even in POSIX mode! [Busybox awk 1.11.3] yes [mawk 1.3.3] yes [nawk (solaris 2.8)] no no [tawk x.xx] unknown no [NetBSD? awk 20030729] no [jawk 1.02] 
no