add oop example

Author: perazz

example/system/CMakeLists.txt

@@ -2,3 +2,4 @@ ADD_EXAMPLE(process_1)
 ADD_EXAMPLE(process_2)
 ADD_EXAMPLE(process_3)
 ADD_EXAMPLE(process_4)
+ADD_EXAMPLE(process_5)

example/system/example_process_5.f90

@@ -0,0 +1,25 @@
+! Process example 5: Object-oriented interface
+program example_process_5
+    use stdlib_system, only: process_type, runasync, is_windows, sleep
+    implicit none
+    type(process_type) :: process
+
+    if (is_windows()) then
+        process = runasync("ping -n 10 127.0.0.1")
+    else
+        process = runasync("ping -c 10 127.0.0.1")
+    endif
+
+    ! Verify the process is running
+    do while (process%is_running())
+        
+        ! Wait a bit before killing the process
+        call sleep(millisec=1500)
+        
+        print *, "Process has been running for ",process%elapsed()," seconds..."
+
+    end do
+    
+    print *, "Process ",process%id," completed in ",process%elapsed()," seconds."
+    
+end program example_process_5