| Command | Description |
| --- | --- |
-| `composer require vendor/package`. | Adds `package` from `vendor` to composer.json's `require` section and installs it |
+| `composer require vendor/package` | Adds `package` from `vendor` to composer.json's `require` section and installs it |
| --- | --- |
| `composer require vendor/package --dev` | Adds `package` from `vendor` to composer.json's `require-dev` section and installs it. |
COPY --chown=user:group host_file.xyz /path/container_file.xyz
```
+### Run commands in strict shell
+
+```docker
+ENV my_var
+SHELL ["/bin/bash", "-euo", "pipefail", "-c"]
+
+# With strict mode:
+RUN false # fails build like using &&
+RUN echo "$myvar" # will throw error due to typo
+RUN true | false # will bail out of pipe
+```
+
+Using `shell` will turn on strict mode for shell commands.
+
### Onbuild
```docker