Need to write a Regex in docker-compose environment variable

I’m trying to write this environment variable:

ExpectedRegex=^[\\"rn ]*A\$$$$

(Meaning: allow [, ", r, n, (space)] for any number of times, then require "A$". Matching the start and end of the string)

docker-compose.yml snap:

environment:
 - ExpectedRegex=^[\\"rn ]*A\$$$$

But docker-compose returns me this regex:

REGEX=^[\\\"rn ]*A\\$$

The problem lies in the last dollar which docker-compose adds another \ before it.

Inside the container I’m using .Net Core to match the regex. When debug-printing the string received I see the double backslash

How can I write the regex in the docker-compose yaml file so that it doesn’t get double backslashed?

>Solution :

I assume, regex is in environment variables, yes?
You can use single quotes to escape it. Something like this:

version: '3.7'

services:

  something:
    image: something:latest
    environment:
      REGEX: '^[\\"rn ]*A\$$$$' 
      // more parameters below

also i think last 4 $ signs are wrong here, seems like only first not escaped is took into account, i think you need to escape all of them, but the last one:

      REGEX: '^[\\"rn ]*A\$\$\$$' 

Last one to match end of string, i mean.