execv

Darryl Scott darryls@productcosting.com
Wed Apr 7 15:03:00 GMT 2004


Hi!

I cannot find any reference to a problem with this in the Cygwin docs.

Is there a display problem for Xapp2 when instigated using a execv call 
from an X-app compiled in cygwin?  Actually it is a three app connection,

         App1 -> A fork function -> App2

The requirement being to allow App1 to be used as if app2 did not exist.

example


IN app1 :
........
system("fork_func app2");
.........


Fork_func : // this (should) start a function as an independent process 
from the orphaned parent allowing it to progress as normal. While the 
fork_func dies.

main(rgc,argv)
......
execv(argv[1],args);
...

All standard stuff.

As usual this is code that is operational elsewhere. In addition if the 
second  X-apps has been compiled using Interix and not cygwin it is also OK.

 From monitoring I can see the second app stops as it attempts to display. 
It passs through all of the screen build and even the XtRealizeWidget and 
stops on entry to the XtAppMainLoop.

If the execv is replaced by a simple system call, system("app2"); then app2 
is displayed OK but at the expense of pausing the calling process..

Obviously the second app is 100% ok when not called from the prompt..

Although the App2 finds the appcontext etc and all seems well during the 
build process when it comes to really display the graphics it slips into a 
close down. and terminates.

Any input gratefully received.





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