touch: safer approach

Author: scivision

+stdlib/touch.m

@@ -2,15 +2,11 @@
 
 function ok = touch(file)
 
-ok = stdlib.exists(file);
-
-if ~ok
-  fid = fopen(file, "w");
-  ok = fid > 0 && fclose(fid) == 0;
-end
+fid = fopen(file, 'a');
+ok = fid > 0 && fclose(fid) == 0;
 
 if ok
-  ok = stdlib.set_modtime(file, datetime("now"));
+  ok = stdlib.set_modtime(file, datetime('now'));
 end
 
 end

test/TestDisk.m

@@ -89,7 +89,7 @@ function test_is_mount(tc, B_ps)
 
 
 function test_hard_link_count(tc, B_jps)
-fn = "test_hard_link_count.txt";
+fn = 'test_hard_link_count.txt';
 tc.assertTrue(stdlib.touch(fn))
 
 [i, b] = stdlib.hard_link_count(fn, B_jps);
@@ -136,7 +136,7 @@ function test_is_dev_drive(tc, B_ps)
 function test_remove_file(tc)
 tc.assumeFalse(stdlib.matlabOlderThan('R2018a'), 'test shaky on Matlab < R2018a')
 
-f = "test_remove.tmp";
+f = 'test_remove.tmp';
 
 tc.verifyFalse(stdlib.remove(f), "should not succeed at removing non-existant path")