linux - How to remove all lines from a text file starting at first empty line?

Question

What is the best way to remove all lines from a text file starting at first empty line in Bash? External tools (awk, sed...) can be used!

Example

1: ABC
2: DEF
3:
4: GHI

Line 3 and 4 should be removed and the remaining content should be saved in a new file.

Answer 1

With GNU sed:

sed '/^$/Q' "input_file.txt" > "output_file.txt"