Question: I need to remove only the `LF`, not `CRLF`. Any idea about that? 

I can use PHP, notepad++, shell script, etc

![enter image description here](https://i.stack.imgur.com/0JUhH.png)

Answer: 
In notepad++

Try this : `(?<!\r)\n`

Make sure to set the option for regular expression in the search options, hope it helps
In Notepad++, you use Search/Replace, tick extended (lower-left) and replace

```
\n

```

by nothing.