How to escape indicator characters (i.e. : or - ) in YAML

Question

In a config file, I have a key to which I wish to assign a URL. The problem is that YAML interprets : and - characters as either creating mappings or lists, so it has a problem with the line

url: http://www.example-site.com/

(both because of the colon following http and the hyphen in the middle)

Is there an explicit way to escape ':' and '-' ? Or would it work to just put the whole thing in single quotes and call it a day?

Answer 1

Quotes:

"url: http://www.example-site.com/"

To clarify, I meant “quote the value” and originally thought the entire thing was the value. If http://www.example-site.com/ is the value, just quote it like so:

url: "http://www.example-site.com/"

Answer 2

What also works and is even nicer for long, multiline texts, is putting your text indented on the next line, after a pipe or greater-than sign:

text: >
    Op dit plein stond het hoofdkantoor van de NIROM: Nederlands Indische 
    Radio Omroep

A pipe preserves newlines, a gt-sign turns all the following lines into one long string.

Answer 3

According to the YAML spec, neither the : nor the - should be a problem. : is only a key separator with a space after it, and - is only an array indicator at the start of a line with a space after it.

But if your YAML implementation has a problem with it, you potentially have lots of options:

- url: 'http://www.example-site.com/'
- url: "http://www.example-site.com/"
- url:
    http://www.example-site.com/
- url: >-
    http://www.example-site.com/
- url: |-
    http://www.example-site.com/

There is explicitly no form of escaping possible in "plain style", however.

Answer 4

Quotes, but I prefer them on the just the value:

url: "http://www.example.com/"

Putting them across the whole line looks like it might cause problems.

Answer 5

Another way that works with the YAML parser used in Jekyll:

title: My Life: A Memoir

Colons not followed by spaces don't seem to bother Jekyll's YAML parser, on the other hand. Neither do dashes.

Answer 6

If you're using @ConfigurationProperties with Spring Boot 2 to inject maps with keys that contain colons then you need an additional level of escaping using square brackets inside the quotes because spring only allows alphanumeric and '-' characters, stripping out the rest. Your new key would look like this:

"[8.11.32.120:8000]": GoogleMapsKeyforThisDomain

See this github issue for reference.

Answer 7

I came here trying to get my Azure DevOps Command Line task working. The thing that worked for me was using the pipe (|) character. Using > did not work.

Example:

steps:
- task: CmdLine@2
  inputs:
    script: |
      echo "Selecting Mono version..."
      /bin/bash -c "sudo $AGENT_HOMEDIRECTORY/scripts/select-xamarin-sdk.sh 5_18_1"
      echo "Selecting Xcode version..."
      /bin/bash -c "echo '##vso[task.setvariable variable=MD_APPLE_SDK_ROOT;]'/Applications/Xcode_10.2.1.app;sudo xcode-select --switch /Applications/Xcode_10.2.1.app/Contents/Developer"