ipcBeginprocess!

Hi zfeng

I think solution 1832836 will be useful in explaining this. You can resolve the problem by adding a small timeout value to ipcReadProcess. E.g.

ipcReadProcess(readBeginTimelpc 1)

OR

You can use ipcWait:

readBeginTimeIpc=ipcBeginProcess("date")
ipcWait(readBeginTimelpc)
simulationBeginTime=ipcReadProcess(readBeginTimeIpc)

Best regards
Quek

 In general you should call ipcWaitForProcess() before calling ipcReadProcess - this waits until the process is up and running and ready to be communicated with. Alternatively use ipcWait as Quek suggested to wait until the process has ended - the choice would depend on whether you really want to wait for it to finish.

Regards,

Andrew.

Hi,

  thanks! it works well, and we don't have to use ipcStopProcess() or ipcKillProcess() after the ipcBeginProcess, i noticed that the exitStatus is set to "0"   after the the ipcBeginProcess() is exacuted, is it normal?

Regards,

zfeng

 Zfeng,

The exit status of what? The return value of ipcGetExitStatus? It will return 0 if the process is still running (ipcIsAliveProcess will tell you this) and 0 if the exit status really was 0 once it has finished.

Andrew.

 Hi,

 yes, the function likes this

newIpc=ipcBeginProcess(myipc)  ; open an image viewer,such as "eog" in linux

;;;some seconds later, i close the "eog" by clicking the close button 

ipcIsActiveProcess(newIpc)  ;; it will return nil

ipcGetExitStatus(newIpc)  ;; it will return 0

so , my question is that: if the ipcKillProcess(newIpc) equal to click the close button of software window , which function can be used to close the ipc, ipcKillProcess(newIpc)? or the ipc will close automatically after closing the software window?

Didn't you just answer this yourself? ipcIsActiveProcess tells you whether it is running (and not stopped). ipcIsAliveProcess() tells you whether it is running at all (even if stopped - by stopped I mean has been sent a STOP signal - as would happen if you called ipcStopProcess(); if you call that, the process is not active, but is alive).

It doesn't matter whether the process has been completed via you closing the window or ipcKillProcess being called - in both cases it ends.

If you use the asynchronous approach with ipcBeginProcess() - i.e. you pass a data, error and exit handler function name, the exit handler will be invoked when the process ends (however it ends).

Regards,

Andrew.