How to pass a Matlab variable to shell environment?

Good morning,

I have the same problem apperntly aksed in this thread

https://it.mathworks.com/matlabcentral/answers/317586-how-to-pass-a-variable-to-a-unix-command-e-g-sed-inside-a-matlab-script?s_tid=gn_loc_drop

but not solved.

I need to pass a variable from matlab to UNIX shell. Let's say I want to print a variable defined within Matlab workspace using "echo" (let's skip for the moment why I would want to do it). This was my attempt

for i=1:9
! echo ${i}
end

but it does not work. How can I pass then a variable defined in Matlab to UNIX environment?

Thanks and best regards

Answer 1

[Shivam]

You can use system command in matlab , here is one use case -

% Define variables
var1 = 'Hello';
var2 = 'world';

% Construct the command
command = ['echo ', var1, ' ', var2];

% Execute the command
system(command);

Output - Hello World

Learn More about system commands - Execute operating system command and return output - MATLAB system - MathWorks India

[Walter Roberson]

If the var* values contain shell meta characters, then this approach can end up a little different than the echo ${i} approach in shell. Best would be to add quotes, like

% Define variables
var1 = 'Hello';
var2 = 'world';

% Construct the command
command = "echo '" + var1 + "' '" + var2 + "'"

command = "echo 'Hello' 'world'"

% Execute the command
system(command);

Hello world