Using GitHub Actions Environment Variables

In GitHub Actions, environment variables can be set and used within workflow files using a combination of literal values and expressions. One of the key benefits of using environment variables is that they can be reused across multiple requests, making it easier to manage complex workflows.

### Setting Multi-Line Output Values

Environment variables can also be set with multi-line output values, similar to how multi-line strings are defined in the 'Multiline Strings' section. This allows for more flexibility when setting and using environment variables.

### Programmatically Setting Environment Variables

Expressions can be used to programmatically set environment variables within workflow files, making it easier to manage complex workflows. Additionally, context-aware access is also available, allowing developers to access and use environment variables in a more flexible way.

### Common Environment Variable Use Cases

Common uses for environment variables include setting base URLs, authentication tokens, and resource IDs. These values can be reused across multiple requests, reducing the complexity of managing workflow files.

### Toolkit Functions and Environment Variables

The following table outlines which toolkit functions are available within a GitHub Actions workflow:

| Toolkit Function | Accessible Using |

| --- | --- |

| GITHUB_PATH | Environment File |

| GITHUB_ENV | Environment File |

| INPUT_ | Environment Variable |

### Example: Creating an Annotation for Build Error

Here is an example of how to create an annotation for a build error using GitHub Actions:

```yaml

name: Create annotation for build error

run: Write-Output '::error file=app.js,line=1::Missing semicolon'

```

This code sets the environment variable `GITHUB_ENV` with the value `::error file=app.js,line=1::Missing semicolon`, which can be used to create an annotation for a build error.

###

In this article, we have explored how GitHub Actions environment variables can be set and used within workflow files. We have also discussed common use cases and examples of how to create annotations for build errors. By using environment variables, developers can reduce the complexity of managing workflow files and make it easier to reuse values across multiple requests.

Github actions environment variables