Remove everything except some word from every line

Question

I am trying to find a regex solution to keep 
 and remove other things without breaking the line order. Only some of the lines contains this pattern one or more times. I tried (?<=&#xA;)(.+)|(.+)(?=&#xA;)|^((?!&#xA;).)*$, but it only keeps one from each row, although they contain more. For example, I have something like that:

The client requires photos of a radioactive world
Reach the target planet.
The client requires photos.

Reach the target planet.
The client requires photos of a desert world
Reach the target planet.
The client requires photos of an airless world. Reach the target planet.
The client requires photos of a strange world

Reach the target planet
Make a quick scan.

Expecting exactly this:














I would be glad if you help.

Answer 1

You can make use of SKIP FAIL to match 
 and then not consume the match.

Then match all characters except &, and when it does encounter &, assert that it is not directly followed by #xA;

Find what


(*SKIP)(*FAIL)|[^&\r\n]+(?:&(?!#xA;)[^&\r\n]*)*

Replace with:

Leave empty

Explanation

• #xA; Match literally
• (*SKIP)(*FAIL)| Consume the characters that you want to avoid
• [^&\r\n]+ Match 1+ times any char except & or a newline
• (?: Non capture group
  • &(?!#xA;) Match & if not directly followed by #xA;
  • [^&\r\n]* Match 0+ times any char except & or a newline
• )* Close the non capture group and repeat 0+ times

Regex demo

Answer 2

You could use a capturing group.

(.*?)((?:
){0,})

Details:

• (.*?): Group1 - matches any characters as few as possible
• ((?:
){0,}): Group2 - matches 
 or not

Demo

Answer 3

You can use the following RegEx to match everything except &#xA

[^
\n]+

Demo