ubuntu-buildroot/output/build/host-gawk-5.2.0/awklib/eg/misc/findpat.awk

{
    if ($1 == "FIND")
        regex = $2
    else {
        where = match($0, regex)
        if (where != 0)
            print "Match of", regex, "found at", where, "in", $0
       }
}