set_modtime shell fallback

Author: scivision

+stdlib/+sys/set_modtime.m

@@ -0,0 +1,19 @@
+function ok = set_modtime(p, t)
+
+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
+  % https://man7.org/linux/man-pages/man1/touch.1.html
+  cmd = sprintf("touch -t %s %s", string(t, "yyyyMMddHHmm"), p);
+end
+
+[s, m] = system(cmd);
+ok = s == 0;
+
+if ~ok
+  warning("stdlib:set_modtime:ValueError", "%s   set modification time of %s: %s", cmd, p, m);
+end
+
+end

+stdlib/set_modtime.m

@@ -3,7 +3,7 @@
 
 function ok = set_modtime(p, t)
 arguments
-  p {mustBeTextScalar}
+  p {mustBeTextScalar, mustBeFile}
   t (1,1) datetime
 end
 
@@ -24,6 +24,10 @@
   ok = stdlib.python.set_modtime(p, utc);
 end
 
+if ~ok
+  ok = stdlib.sys.set_modtime(p, t);
+end
+
 end
 
 %!test

+stdlib/touch.m

@@ -6,7 +6,9 @@
   t (1,1) datetime = datetime("now")
 end
 
-if ~stdlib.exists(p)
+ok = stdlib.exists(p);
+
+if ~ok
   fid = fopen(p, "w");
   ok = fid > 0 && fclose(fid) == 0;
 end

test/TestTime.m

@@ -32,9 +32,7 @@ function test_get_modtime(tc)
 
 
 function test_touch_modtime(tc)
-tc.assumeTrue(stdlib.has_java() || stdlib.has_python())
-
-fn = fullfile(tc.td, "modtime.txt");
+fn = tc.td + "/modtime.txt";
 
 tc.verifyTrue(stdlib.touch(fn, datetime("yesterday")))
 t0 = stdlib.get_modtime(fn);
@@ -45,14 +43,23 @@ function test_touch_modtime(tc)
 tc.verifyGreaterThanOrEqual(t1, t0)
 end
 
-
-function test_set_modtime(tc)
-tc.assumeTrue(stdlib.has_java() || stdlib.has_python())
-  
-tc.verifyEqual(stdlib.set_modtime("", datetime("now")), false)
 end
 
 
+methods(Test, TestTags="shell")
+
+function test_set_modtime_sys(tc)
+fn = tc.td + "/modtime.txt";
+
+tc.verifyTrue(stdlib.touch(fn, datetime("yesterday")))
+t0 = stdlib.get_modtime(fn);
+
+tc.verifyTrue(stdlib.set_modtime(fn, datetime("now")))
+t1 = stdlib.get_modtime(fn);
+
+tc.verifyGreaterThanOrEqual(t1, t0);
+end
+
 end
 
 end