awk and sed + append text after last line in file

Question

how to append text line after the last line in file without using echo command need example in sed and awk THX yael

Answer 1

echo "Append this line" >> file.txt

Answer 2

Here's how you do it without sed:

echo "Hello World" >> file.txt

Here's how you do it with sed:

sed -i '$aHello World' file.txt

Answer 3

It's pretty easy to add lines with awk by using the END matcher:

awk '{print}END{print "another line"}' input_file

Answer 4

Without using echo:

awk 'BEGIN {print "line of text"}' >> file.txt

printf "line of text\n" >> file.txt

cat <<< "line of text" >> file.txt

cat <<EOF >> file.txt
line of text
EOF

head -c 1 /dev/zero | sed 's/./line of text\n/' >> file.txt

read -p $'line of text\n' -t .00012 2>> file.txt