set_modtime shell fallback

Author: scivision

+stdlib/set_modtime.m

@@ -24,6 +24,23 @@
   ok = stdlib.python.set_modtime(p, utc);
 end
 
+if ok, return, end
+
+if ispc()
+  cmd = sprintf('pwsh -Command "(Get-Item ''%s'').LastWriteTime = ''%s''"', p, string(t, "yyyy-MM-dd HH:mm:ss"));
+elseif ismac()
+  cmd = sprintf("touch -mt %s %s", string(t, "yyyyMMddHHmm"), p);
+else
+  cmd = sprintf("touch -d '%s' %s", string(t, "yyyy-MM-dd HH:mm:ss"), p);
+end
+
+[s, m] = system(cmd);
+ok = s == 0;
+
+if ~ok
+  warning("stdlib:set_modtime:ValueError", "Failed to set modification time of %s: %s", p, m);
+end
+
 end
 
 %!test

test/TestTime.m

@@ -32,8 +32,6 @@ function test_get_modtime(tc)
 
 
 function test_touch_modtime(tc)
-tc.assumeTrue(stdlib.has_java() || stdlib.has_python())
-
 fn = fullfile(tc.td, "modtime.txt");
 
 tc.verifyTrue(stdlib.touch(fn, datetime("yesterday")))
@@ -47,8 +45,6 @@ function test_touch_modtime(tc)
 
 
 function test_set_modtime(tc)
-tc.assumeTrue(stdlib.has_java() || stdlib.has_python())
-  
 tc.verifyEqual(stdlib.set_modtime("", datetime("now")), false)
 end