Well , I am using following command in TCL :- exec typeperf -cf input.txt -si 1 -o output.txt & Now if i run the TCL script individually by in my application it works. Now i want to automate this process for executing multiple such scripts for which i am trying to use perl.

and then what happened?

You say SYSTEM Call of PERL hangs application when running a TCL script

hang means it doesn't run in the background

If you want to run it in background use Proc::Background

Ok, i will be a more descriptive this time ...

Say my application name is test.exe.
To run the application i use input1.tcl.

When i run the application individually using tcl , I can see from task manager of windows that test.exe is running and once my tcl completes , the .exe file is killed.

This input1.tcl also contains typeperf command running in background as mentioned below. Once the TCL is run . i kill the typeperf forcibly using "exec TASKKILL typeperf.exe" written at the end of input1.tcl.

Now i have multiple such TCL's which i have run on same test.exe. I am writing something like below :-
foreach $tcl (list_of_tcls)
{
system ("test.exe", "TCL:$tcl" );
}
What this is doing is that i invokes a new process for test.exe on every iteration. Once the tcl is complete , it automatically terminate the test.exe.
But after few iterations , i can see that test.exe has begun to run , but it is not completing its execution. test.exe just sits there (this is what i meant by hang).
I forcibly kill the process from task manager , and then the perl again starts the scripts from last iteration.