The following exec script will locate all markdown code blocks within the
file and process based on their filetype tag:

Edit , x/\n```@*?```\n/ {
  n/file\n(.*)\n/ {
    p/\n:: FILE\n/;
    $"head -n 5 {1}";
  };

  n/url\n(.*)\n/ {
    p/\n:: URL\n/;
    $"curl -s {1}";
  };
}

```file
../../../README.md
```

```file
../../../Cargo.toml
```

```url
http://example.com
```

```url
http://wttr.in?format=%c%t\n
```
