Sofia-SIP is an open-source SIP User-Agent library, compliant with the IETF RFC3261 specification. It can be used as a building block for SIP client software for uses such as VoIP, IM, and many other real-time and person-to-person communicat

linux初级用户指南，为初学者学习linux提供了很好的学习资料，容易被理解和接收。-linux primary user guide for beginners to learn linux to provide a good learning materials, easy to understand and receive.

indicates the last selected message. If primary selection is not in mailtool, and user clicks on a button, this message is the one operated upon. mt_last_sel_msg is set in mt_update_curmsg, and in mt_set_curselmsg.