There are two ways to use a Codefresh variable in your pipelines:

1. By default all variables will be exposed as UNIX environment variables in all freestyle steps as`$MY_VARIABLE_EXAMPLE`.

1. Variables can be used in YAML properties with the syntax {% raw %}`${{MY_VARIABLE_EXAMPLE}}`{% endraw %}.

1. Expose as UNIX environment variables

This is the default method, where all variables in all freestyle steps are exposed as UNIX environment variables:`$MY_VARIABLE_EXAMPLE`.

1. Directly in YAML properties

Use variables can be used in YAML properties with the syntax {% raw %}`${{MY_VARIABLE_EXAMPLE}}`{% endraw %}.

For example, you can print out the branch as an environment variable like this:

**Example: Print out the branch as an environment variable**

In this example, we use simple`echo` commands, but any program or script that reads environment variables can also read them in the same manner.

{% highlight yaml %}

{% endraw %}

{% endhighlight %}

In the example above we are using simple`echo` commands, but any program or script that reads environment variables could also read them in the same manner.

Using variables directly inyaml properties can be done like this:

**Example: Use directly inYAML properties**

{% highlight yaml %}

{% endraw %}

{% endhighlight %}

You can also concatenate variables:

**Example: Concatenating variables**

{% highlight yaml %}

{% endraw %}

{% endhighlight %}

This will create docker images with tags such as:

The concatenation above creates Docker images with tags such as:

Notice that this syntax is specific to Codefresh and is**only** available within the Codefresh YAML file itself. If you want to write scripts or programs that use the Codefresh variables, you need to make them aware of the environment variable form.

Steps defined inside steps are scoped to the step they were created in (even if you used the`export` command). In order to allow using variables across steps, we provide a shared file that facilitates variables importing and exporting. There are two ways to add variables to this file:

Steps defined within steps are scoped to the step they were created in (even if you used the`export` command). To use variables across steps, we provide a shared file through which you can import and export variables.

There are two ways to add variables to the shared file:

* Using the`cf_export` command

* Writing directly to the file

Within every freestyle step, the`cf_export` command allows you to export variables across steps(by writing to the shared variables file).

Within every freestyle step, the`cf_export` command allows you to export variables across steps by writing to the shared variables file.

You can either:

- Explicitly state a VAR=VAL pair

{% endraw %}

{% endhighlight %}

Notice that`cf_export` has the same syntax structure as the[bash export command](https://www.gnu.org/software/bash/manual/html_node/Environment.html){:target="\_blank"}. This means that when you use it you**don't** need any dollar signs for the variable created/assigned.

<br>

`cf_export` has the same syntax as the[bash export command](https://www.gnu.org/software/bash/manual/html_node/Environment.html){:target="\_blank"}.

This means that when you use it you**don't** need any dollar signs for the variable that is created/assigned.

Also notice that`cf_export` works on*subsequent* steps only. If you want to export a variable right away in the present step and all the rest of the steps you need to do the following:

<br>

By default,`cf_export` works only on*subsequent* steps.

To export a variable both in the current and to all the remaining steps, do the following:

There is nothing really magic about`cf_export`. It is a normal script. You can see its contents on your own by entering the command`cat /codefresh/volume/cf_export` on any[Codefresh freestyle step]({{site.baseurl}}/docs/pipelines/steps/freestyle/) inside a pipeline.

For more information on its limitations see the[troubleshooting page]({{site.baseurl}}/docs/troubleshooting/common-issues/cf-export-limitations/).

There is nothing really magical about`cf_export`. It is a normal script. You can see its contents on your own by entering the command`cat /codefresh/volume/cf_export` on any[Codefresh freestyle step]({{site.baseurl}}/docs/pipelines/steps/freestyle/) inside a pipeline.

For more information on its limitations, see the[troubleshooting page]({{site.baseurl}}/docs/troubleshooting/common-issues/cf-export-limitations/).

For more advanced use cases, you can write directly to the shared variable file that Codefresh reads to understand which variables need to be available to all steps. This file has a simple format where each line is a variable and its value in the form of`VARIABLE=VALUE`. The`cf_export` command mentioned in the previous section is just a shorthand for writing on this file.

For more advanced use cases, you can write directly to the shared variable file that Codefresh reads to understand which variables need to be available to all steps.

This file has a simple format where each line is a variable and its value in the form of`VARIABLE=VALUE`. The`cf_export` command mentioned in the previous section is just a shorthand for writing on this file.

The variables file is available inside freestyle steps in the following path:**`{% raw %}${{CF_VOLUME_PATH}}{% endraw %}/env_vars_to_export`**

Codefresh has the built-incapabililty to automatically mask variables in logs if they are encrypted. The values of encrypted variables will be replaced with asterisks in build logs.

Codefresh has the built-incapability to automatically mask variables in logs if they are encrypted. The values of encrypted variables will be replaced with asterisks in build logs.

{% include

image.html

When passing special characters through environmental variables`\` can be used as an escape character. For example if you were passing a cassandra connection string you might do something like`Points\=hostname\;Port\=16376\;Username\=user\;Password\=password`

When you run a pipeline manually, you can either add variables on the fly or change the value of existing variables for the specific run of the build.

You can also encrypt the build-specific variables, new or existing, at the same time.

1. Do one of the following:

* From the Pipelines page, select the pipeline and click**Run** on the right.

* From the Builds page, select the pipeline to run manually, and then click**Run**.

1. Expand Build Variables.

1. To add a variable, click**Add Variable**.

1. Enter the**Key** and**Value** for the new variable.

1. To encrypt, click {::nomarkdown}<imgsrc="../../../images/icons/encrypt.png"display=inline-block> <b>Encrypt</b>{:/}, and confirm.

{% include

image.html

lightbox="true"

file="/images/pipeline/variables/encrypt-build-variable.png"

url="/images/pipeline/variables/encrypt-build-variable.png"

alt="Encrypt variable for build run"

caption="Encrypt variable for build run"

max-width="50%"

%}

When passing special characters through environmental variables, use`\` as an escape character.

For example, to pass a cassandra connection string, you might do something like`Points\=hostname\;Port\=16376\;Username\=user\;Password\=password`.

This will safely escape`;` and`=`.