# Conditional Logic in a Script Section in a Gitlab Pipeline

# Problem Statement

To check if a variable in a GitLab CI/CD pipeline's `script` section is not an empty string, you can use standard shell scripting conditional logic.

# Approaches

## Using Bash/Shell:

The most common and robust way to check for a non-empty string in a Bash/Shell script within your `script` section is to use the `-n` operator within an `if` statement.

Code

```
your_job:
  script:
    - if [ -n "$MY_VARIABLE" ]; then
    -   echo "MY_VARIABLE is not empty: $MY_VARIABLE"
    - else
    -   echo "MY_VARIABLE is empty."
    - fi
```

Explanation:

-   `if [ -n "$MY_VARIABLE" ]`: This checks if the length of the string `$MY_VARIABLE` is greater than zero. The double quotes around `$MY_VARIABLE` are crucial to prevent word splitting and globbing issues if the variable contains spaces or special characters.
-   `then` and `else`: Standard shell `if` statement constructs.
-   `fi`: Closes the `if` statement.

## Alternative (less preferred for general use, but works):

You can also directly compare the variable to an empty string:

Code

```
your_job:
  script:
    - if [ "$MY_VARIABLE" != "" ]; then
    -   echo "MY_VARIABLE is not empty: $MY_VARIABLE"
    - else
    -   echo "MY_VARIABLE is empty."
    - fi
```

# Important Considerations:

-   **Variable Export:**

    If `MY_VARIABLE` is set in a `before_script` or a preceding `script` block and you want it available in subsequent lines or jobs, ensure it is exported (e.g., `export MY_VARIABLE="value"`).

-   **Shell Environment:**

    The specific shell syntax might vary slightly depending on the shell used by your GitLab Runner (e.g., `bash`, `sh`, `PowerShell`). The examples above are for Bash/sh, which are commonly used.