Calling Powershell from MATLAB: AWS Example

Running 2014A and Windows Server 2012 R2. I wish to call Powershell from inside matlab. Below is my attempt,

%%Get The required Data
[~, instance_ID] = system('powershell 2*10; echo "GET-EC2-Instance"');
[~, region_id] = system('powershell 2*10; echo "GET-AWSRegion"');
Terminate_param = true; % stop or terminate?
if(Terminate_param)
    %terminate the instance
    [status,cmdout] = system(['powershell 2*10; echo "Stop-EC2Instance -Instance' instance_ID ' -Region' region_id '-Terminate' '-Force"']);
else
    %stop the instance
    [status,cmdout] = system(['powershell 2*10; echo "Stop-EC2Instance -Instance' instance_ID ' -Region' region_id '-Force"']);
end

As you can see what I am unclear on is how to differentiate between Powershell and AWS Powershell. When I run the above commands I get the below (which is not the response I want),

[~, instance_ID] = system('powershell 2*10; echo "GET-EC2-Instance"')
instance_ID =
20
GET-EC2-Instance

When I open the executable "Windows Powershell for AWS" (as per AWS Powershell) and type the command lines, i get the below (Note I have already entered my access key, secret key and region).

    PS C:\Program Files (x86)\AWS Tools\PowerShell\AWSPowerShell> Get-AWSRegion

    Region                                  Name                                                             IsShellDefault
    ------                                  ----                                                             --------------
    us-east-1                               US East (Virginia)                                                         True
    us-west-1                               US West (N. California)                                                   False
    us-west-2                               US West (Oregon)                                                          False
    eu-west-1                               EU West (Ireland)                                                         False
    ap-northeast-1                          Asia Pacific (Tokyo)                                                      False
    ap-southeast-1                          Asia Pacific (Singapore)                                                  False
    ap-southeast-2                          Asia Pacific (Sydney)                                                     False
    sa-east-1                               South America (Sao Paulo)                                                 False

PS C:\Program Files (x86)\AWS Tools\PowerShell\AWSPowerShell> GET-EC2Instance

GroupNames    : {}
Groups        : {}
Instances     : {my_key_name, my_key_name, my_key_name, my_key_name...}
OwnerId       : aws_account_id
RequesterId   :
ReservationId : r-be212395

GroupNames    : {}
Groups        : {}
Instances     : {my_key_name}
OwnerId       : aws_account_id
RequesterId   :
ReservationId : r-bbeac492

GroupNames    : {}
Groups        : {}
Instances     : {my_key_name}
OwnerId       : aws_account_id
RequesterId   :
ReservationId : r-15efd42f

GroupNames    : {}
Groups        : {}
Instances     : {my_key_name}
OwnerId       : aws_account_id
RequesterId   :
ReservationId : r-dc3133f2

However, none of these correspond to the instance_id of the machine from which I am making this call.

Then I run the below, getting the instance_id from the AWS management console window,

PS C:\Program Files (x86)\AWS Tools\PowerShell\AWSPowerShell> Stop-EC2Instance -Instance i-2810d7c6

This then stops the instance as it's supposed to.

Hence I am happy the commands work. I would just like to be able to execute these from inside MATLAB.

Also keen to hear from anyone who was experience with the AWS command line interface (CLI) tool.

thank you.

[Geoff Hayes]

Try using system or the exclamation point. An example of the latter and powershell seems to be found at How do I execute Powershell scripts in MATLAB.

[Matlab2010]

temp answer: You need to write bat files that speak to aws powershell (which does not have an exe, only a dll). system.m then calls the bat file. to be updated when ive got it working...

Answer 1

[Greg]

I'm not totally clear on what the actual question is. However, I'm taking a decent guess that your problem is the "echo" in your system command. In Windows system calls, "ECHO" is like MATLAB's "DISP". It purely prints the string back to you, there is no command being executed.