You can use the following code snippet :
java -XX:+PrintFlagsFinal -Xms512m -Xmx1024m -Xss512k -XX:PermSize=64m -XX:MaxPermSize=128m
-version | grep -iE 'HeapSize|PermSize|ThreadStackSize'
In my pc I am getting following output :
uintx InitialHeapSize := 536870912 {product}
uintx MaxHeapSize := 1073741824 {product}
uintx PermSize := 67108864 {pd product}
uintx MaxPermSize := 134217728 {pd product}
intx ThreadStackSize := 512 {pd product}