header.awk

#!/usr/bin/nawk -f
BEGIN {
    cmd = "/usr/bin/tput lines"
    cmd | getline lines
    close(cmd)

    cmd = "/usr/bin/tput cols"
    cmd | getline cols
    close(cmd)

    cmd = "/usr/bin/tput smul"
    cmd | getline ul
    close(cmd)

    cmd = "/usr/bin/tput rmul"
    cmd | getline noul
    close(cmd)
}

function setscroll(top, bottom) {
    cmd = sprintf("/usr/bin/tput csr %d %d", top - 1, bottom - 1)
    cmd | getline out
    close(cmd)

    printf("%s", out)
}

NR == 1 {
    setscroll(2, lines)
    fmt = sprintf("%%s%%-%ds%%s\n", cols)
    printf(fmt, ul, $0, noul)
    next
}
{ print }
END {
    setscroll(1, lines)
    if (NR < lines) {
        y = NR + 1
    } else {
        y = lines
    }

    cmd = sprintf("/usr/bin/tput cup %d 1", y - 1)
    cmd | getline pos
    close(cmd)

    printf("%s", pos)
}