check if an environment variable exists in matlab

You can use the getenv function in Matlab to check whether an environment variable exists or not. This function returns an empty string if the environment variable does not exist.

Here's an example code snippet to check if the HOME environment variable exists:

main.m
homeVar = getenv('HOME');
if isempty(homeVar)
    disp('HOME environment variable is not set.');
else
    disp(['HOME environment variable is set to: ', homeVar]);
end
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In this code snippet, we first call the getenv function with the name of the environment variable (HOME in this case). If the return value of getenv is an empty string, we print a message saying that the environment variable is not set. Otherwise, we print a message that includes the value of the environment variable.