add installDotNet() helper

Author: scivision

scripts/installDotNet.m

@@ -0,0 +1,63 @@
+%% INSTALL_DOTNET install the .NET SDK
+% this can be used with dotnetenv() etc.
+% https://www.mathworks.com/help/matlab/ref/dotnetenv.html
+
+function installDir = installDotNet(installDir)
+arguments
+  installDir (1,1) string = ""
+end
+
+root = fileparts(fileparts(mfilename('fullpath')));
+addpath(root)
+
+if ispc()
+  cmd = "winget install Microsoft.DotNet.SDK.9";
+else
+
+if ~strlength(installDir)
+  if ispc()
+    installDir = getenv("USERPROFILE");
+  else
+    installDir = getenv("HOME");
+  end
+  installDir = fullfile(installDir, '.dotnet');
+end
+if ~isfolder(installDir)
+  mkdir(installDir);
+end
+
+url = 'https://dot.net/v1/dotnet-install.sh';
+
+scr = websave(fullfile(installDir, 'dotnet-install.sh'), url);
+
+cmd = sprintf('sh -c "%s --install-dir %s"', scr, installDir);
+
+assert(stdlib.set_permissions(scr, 0, 0, 1), sprintf("chmod +x %s", scr))
+end
+
+disp(cmd)
+
+s = system(cmd);
+ok = 0;
+if ispc()
+  ok(end+1) = -1978335189;
+end
+if ~stdlib.is_matlab_online()
+  assert(ismember(s, ok))
+end
+
+if isunix()
+  setenv("DOTNET_ROOT", installDir)
+
+  disp("add to " + fullfile(userpath, 'startup.m') + " the line:")
+  disp("setenv('DOTNET_ROOT','" + installDir + "')")
+
+  [~, m] = system(sprintf('%s/dotnet --info', installDir));
+  disp(m)
+end
+
+assert(NET.isNETSupported)
+
+dotnetenv()
+
+end