echo style appending, but to the beginning of a file

Question

Is there any nice trick in UNIX shell to append lines to the beginning of a file? E.g. akin to ``` echo "Foobar" >> file.txt ``` ... but instead new lines would prepend the existing ones?

Accepted Answer

In 2 steps:

```
content=$(cat file.txt) # no cat abuse this time
echo -en "foobar
$content" >file.txt
```

echo >> style appending, but to the beginning of a file

Solution

Problem