Hi, I am trying a script to read some headers which are passed from one module to another. c = @cast($frags[0]->f_addr, "volioship_hdr_t", "/root/ngadre/unixvm-cvs/src/common/kernel/vxvm/ioship_cvm.h") printf("Arguments: [Frag[0]->size: %d, Frag[0]->f_addr: %u, Sender: %d, Receiver: %d]\n", $frags[0]->f_size, $frags[0]->f_a ddr, c->iosh_sender, c->iosh_receiver) The header file is locally available on the machine. Error Msg: semantic error: type definition 'volioship_hdr_t' not found in '/root/ngadre/unixvm-cvs/src/common/kernel/vxvm/ioship_cvm.h': operator '@cast' at :46:6 source: c = @cast($frags[0]->f_addr, "volioship_hdr_t", "/root/ngadre/unixvm-cvs/src/common/kernel/vxvm/ioship_cvm.h") How do I make system tap refer to this structure. Thanks