System Exec ignores DOS command

[Raymond Tsang]

Hi LAVAs,

I want to write a VI which "touches" a file. By "touch", I mean, to update the "last modified time" of a file without modifying its content.

Using System Exec.vi, I made a simple VI (attached screenshots), but it doesn't do what it is supposed to do and return no error.

I'm really puzzled . Any ideas?

Ray

[ShaunR]

Wire an indicator to the Standard out and you will see the result from your call to the DOS box. You don't get an error because the SystemExec successfully completed the CMD call. However, the DOS box may not have executed the copy command.

If you look in the windows help, they suggest making a batch file with the command options and calling that.

I personally would use a "Call Function Block Node" to call a windows API to achieve what you are trying to do. (Kernel32.dll has a SetFileTime function). Although there may be an easier/more elegant method.

[asbo]

You could use an alternative approach like the attached to update the timestamp on the file.