Awk - print the number of row between a selected range from variable in awk and increment his value when variable change after user keypress - awk

Question

This question is more further developed with reference to the following case awk print the number of columns between a selected range from awk
I have the next short script:
#!/bin/bash
#Control del buffer
#awk en stackowerflow
#https://stackoverflow.com/questions/74483916/awk-print-the-number-of-columns-between-a-selected-range-from-awk/74483975?noredirect=1#comment131485506_74483975
if [ $# -eq 1 ]; then
FICH="${1}"
else
FICH="donaciones"
fi
#_INIT valores globales para mostrar debajo en la ultima linea
#alto_INIT necesario para poner texto abajo en la ultima linea
alto_INIT=`tput lines`
alto=`expr $alto_INIT - 2`
largo=`tput cols`
TOTAL_LINEAS_INIT=`cat "$FICH" | wc -l`
TOTAL_LINEAS=$TOTAL_LINEAS_INIT
#Mostramos solo las lineas dependiendo del alto del terminal
#Numero de paginas que hay que mostrar
LINEA=`expr $TOTAL_LINEAS - $alto`
NUM_PAG=`echo "scale=1; $TOTAL_LINEAS / $alto"|bc`
#Si el sresto de dividdir NPAG entre n lineas es +0 sumanos 1 pag. mas
if [ "${NUM_PAG##*.}" -gt 0 ]; then
NUM_PAG=`echo "scale=0; ${NUM_PAG}" + 1 |bc`
NUM_PAG=${NUM_PAG%%.*}
fi
buffer=`awk -v total_lineas="$TOTAL_LINEAS" -v linea="$LINEA" 'NR>=linea&&NR<=total_lineas' "$FICH"`
function Arriba(){
TOTAL_LINEAS=`expr $TOTAL_LINEAS - $alto`
DESDE=`expr $TOTAL_LINEAS - $alto`
HASTA=$TOTAL_LINEAS
if [[ $DESDE -lt 0 ]] ; then
DESDE=0
HASTA=`expr $DESDE + $alto`
fi
buffer=`awk -v desde="$DESDE" -v hasta="$HASTA" 'NR>=desde&&NR<=hasta' "$FICH"`
TOTAL_LINEAS=`expr $HASTA + 1`
}
function Abajo(){
DESDE=$TOTAL_LINEAS
HASTA=`expr $TOTAL_LINEAS + $alto`
if [[ $HASTA -gt $TOTAL_LINEAS_INIT ]] ; then
HASTA=$TOTAL_LINEAS_INIT
fi
buffer=`awk -v desde="$DESDE" -v hasta="$HASTA" 'NR>=desde&&NR<=hasta' "$FICH"`
TOTAL_LINEAS=$HASTA
}
while true; do
clear
printf "$buffer"
tput cup $alto_INIT 0 && printf "Total Lineas: $TOTAL_LINEAS_INIT | Total Pag: $NUM_PAG |Buffer: De $DESDE hasta $HASTA | $TOTAL_LINEAS | (w) Ayuda"
read -rsn1 TECLA
case $TECLA in
h) Arriba ;;
j) Abajo ;;
w) Help ;;
q) printf "\n" && break ;;
esac
done
exit 0
The goal here is show the number of line from a range of lines invoked by awk.
The program calculate the global lines of terminal and made a pagination from a file.Like
less, but i want to show only the portion of the file when the user press a "h" or "j" key. Every time the user press the key "h" the buffer ( portion of file) change and show
the correct part of file in dependence of number of rows. And when the user press the "j" key the buffer return to the previous key.
The program works ok but i want that when awk show the buffer , give me the number of line that correspond to this global line of the file. For this, i have the variable $TOTAL_LINEAS that increment or decrement every instruction buffer change. And this buffer instruction show from this TOTAL_LINEAS until the lines of terminal , and this every time the user press key. In the previous answer i can to add this number of line
but when the user press a key for change the new buffer text allways print the number for this buffer but not for the global buffer that correspond to real line of the file. In other words, allways print the number of line but in this portion of text not for the global text.
I.E: if i have
1 1:20220413:20:Curso Astrología:5:Vicente Ferrer
2 1:10042022:0:Donación instituto Samye:103:Propia
3 14:20220428:0:Candelario Yeshe Nyimpo Inc:9:Dudjom Tersar
4 1:20220512:60:Ayuda por el Hambre y Violencia:6:Vicente Ferrer
Total Lineas: 43 | Total Pag: 2 |Buffer: De 0 hasta 26 | 27
but in the next keypress for go to the next page i need:
5 1:20220413:20:111
6 1:10042022:0:22
7 14:20220428:0:33
8 1:20220512:60:44
Total Lineas: 43 | Total Pag: 2 |Buffer: De 27 hasta 43 | 43
and not:
1 1:20220413:20:111
2 1:10042022:0:22
3 14:20220428:0:33
4 1:20220512:60:44
Total Lineas: 43 | Total Pag: 2 |Buffer: De 27 hasta 43 | 43

Answer 1

Finally was easy:
buffer=`echo "$buffer" |awk -v i=$TOTAL_LINEAS 'NR==i !NF{print;next} NF{print ++i, $0}'`
Thanks all !!