• The AWS Systems Manager CloudWatch Dashboard will no longer be available after April 30, 2026. Customers can continue to use Amazon CloudWatch console to view, create, and manage their Amazon CloudWatch dashboards, just as they do today. For more information, see [Amazon CloudWatch Dashboard documentation](https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/CloudWatch_Dashboards.html). 

# Using exit codes in commands
<a name="run-command-handle-exit-status"></a>

In some cases, you might need to manage how your commands are handled by using exit codes.

## Specify exit codes in commands
<a name="command-exit-codes"></a>

Using Run Command, a tool in AWS Systems Manager, you can specify exit codes to determine how commands are handled. By default, the exit code of the last command run in a script is reported as the exit code for the entire script. For example, you have a script that contains three commands. The first one fails but the following ones succeed. Because the final command succeeded, the status of the execution is reported as `succeeded`.

**Shell scripts**  
To fail the entire script at the first command failure, you can include a shell conditional statement to exit the script if any command before the final one fails. Use the following approach.

```
<command 1>
    if [ $? != 0 ]
    then
        exit <N>
    fi
    <command 2>
    <command 3>
```

In the following example, the entire script fails if the first command fails.

```
cd /test
    if [ $? != 0 ]
    then
        echo "Failed"
        exit 1
    fi
    date
```

**PowerShell scripts**  
PowerShell requires that you call `exit` explicitly in your scripts for Run Command to successfully capture the exit code.

```
<command 1>
    if ($?) {<do something>}
    else {exit <N>}
    <command 2>
    <command 3>
    exit <N>
```

Here is an example:

```
cd C:\
    if ($?) {echo "Success"}
    else {exit 1}
    date
```

# Handling reboots when running commands
<a name="send-commands-reboot"></a>

If you use Run Command, a tool in AWS Systems Manager, to run scripts that reboot managed nodes, we recommend that you specify an exit code in your script. If you attempt to reboot a node from a script by using some other mechanism, the script execution status might not be updated correctly, even if the reboot is the last step in your script. For Windows managed nodes, you specify `exit 3010` in your script. For Linux and macOS managed nodes, you specify `exit 194`. The exit code instructs AWS Systems Manager Agent (SSM Agent) to reboot the managed node, and then restart the script after the reboot completed. Before starting the reboot, SSM Agent informs the Systems Manager service in the cloud that communication will be disrupted during the server reboot.

**Note**  
The reboot script can't be part of an `aws:runDocument` plugin. If a document contains the reboot script and another document tries to run that document through the `aws:runDocument` plugin, SSM Agent returns an error.

**Create idempotent scripts**

When developing scripts that reboot managed nodes, make the scripts idempotent so the script execution continues where it left off after the reboot. Idempotent scripts manage state and validate if the action was performed or not. This prevents a step from running multiple times when it's only intended to run once.

Here is an outline example of an idempotent script that reboots a managed node multiple times.

```
$name = Get current computer name
If ($name –ne $desiredName) 
    {
        Rename computer
        exit 3010
    }
            
$domain = Get current domain name
If ($domain –ne $desiredDomain) 
    {
        Join domain
        exit 3010
    }
            
If (desired package not installed) 
    {
        Install package
        exit 3010
    }
```

**Examples**

The following script samples use exit codes to restart managed nodes. The Linux example installs package updates on Amazon Linux, and then restarts the node. The Windows Server example installs the Telnet-Client on the node, and then restarts it. 

------
#### [ Amazon Linux 2 ]

```
#!/bin/bash
yum -y update
needs-restarting -r
if [ $? -eq 1 ]
then
        exit 194
else
        exit 0
fi
```

------
#### [ Windows ]

```
$telnet = Get-WindowsFeature -Name Telnet-Client
if (-not $telnet.Installed)
    { 
        # Install Telnet and then send a reboot request to SSM Agent.
        Install-WindowsFeature -Name "Telnet-Client"
        exit 3010 
    }
```

------