---

#!/bin/bash

INPUT="$1"

sed '/кот/Ii\этот хвастливый' "$INPUT"

#!/bin/bash

INPUT="$1"

awk 'NR % 3 != 0 { if ($1 == "K") $1 = "B"; print }' "$INPUT"

#!/bin/bash

INPUT=$1

awk 'NR==1 {print; next} {if ($1!="H") count++; $2=sin($2); $3=sin($3); $4=sin($4); print} END {print "Число атомов != H:", count}' "$INPUT"