read ignore read ignore index=-1 while read line; do set -- $line index=$((index + 1)) if [ $index != "$1" ]; then while [ $(($1 - $index)) -gt 0 ]; do echo $index 0 index=$((index + 1)) done fi index="$1" [ "$index" -le 1024 ] || break second=1 shift [ $# -le 0 ] || second="$1" echo $index $second done