print Markdown code fences, for a weak version of literate Markdown

print_code_fences.awk

#!/usr/bin/awk -f
BEGIN { in_code_block = 0 }
/^```/ {
    if (!in_code_block) {
        in_code_block = 1;
        first_line = 1;
    } else {
        in_code_block = 0;
        print "";
    }
}
{
    if (in_code_block && !first_line) {
        print;
    }
    first_line = 0;
}

sample

$ cat sample.md
Here is some text,
and some more text.
```javascript
const message = "This is JavaScript!";
```
More text follows, and then
```javascript
console.log(message);
```
$ awk -f print_code_fences.awk sample.md
const message = "This is JavaScript!";

console.log(message);

$ 

I'm aware that this has false positives (with ```inline code``` ) and false negatives (leading whitespace). It's good enough for me right now.