How to break a single command inside a `script` step on multiple lines

Question

We have a project using Azure Pipeline, relying on azure-pipelines.yml file at the repo's root.

When implementing a script step, it is possible to execute successive commands in the same step simply writing them on different lines:

- script: |
  ls -la
  pwd
  echo $VALUE

Yet, if we have a single command that is very long, we would like to be able to break it on several lines in the YAML file, but cannot find the corresponding syntax?

Answer 1

You didn't specify your agent OS so I tested on both windows-latest and ubuntu-latest. Note that the script task runs a bit differently on these 2 environments. On Windows, it uses cmd.exe. On Ubuntu, it uses bash. Therefore, you have to use the correct syntax.

On Windows:

pool:
  vmImage: 'windows-latest'

steps:
- script: |
    mkdir ^
    test ^
    -p ^
    -v

On Ubuntu:

pool:
  vmImage: 'ubuntu-latest'

steps:
- script: |
    mkdir \
    test \
    -p \
    -v

Those two files above work on my Azure DevOps.

Answer 2

At the moment, the only way we found for to break a single command on multiple line is using YAML folded style:

- script: >
    echo
    'hello world'

It is all about replacing | with >.

Notes:

• It is not possible to introduce extra indentation on the following lines! For example, trying to align all arguments given to a command would break the behaviour.
• This style will replace newlines in the provided value with a simple white space. This means the script now can only contain a single command (maybe adding literal \n at the end of the line would actually introduce a linebreak in the string, but it feels backward compared to the usual approach of automatice linebreak unless an explicit continuation is added).