1SYS_SOCKET 1 2SYS_BIND 2 3SYS_CONNECT 3 4SYS_LISTEN 4 5SYS_ACCEPT 5 6SYS_GETSOCKNAME 6 7SYS_GETPEERNAME 7 8SYS_SOCKETPAIR 8 9SYS_SEND 9 10SYS_RECV 10 11SYS_SENDTO 11 12SYS_RECVFROM 12 13SYS_SHUTDOWN 13 14SYS_SETSOCKOPT 14 15SYS_GETSOCKOPT 15 16SYS_SENDMSG 16 17SYS_RECVMSG 17 18SYS_ACCEPT4 18 19SYS_RECVMMSG 19 20SYS_SENDMMSG 20 21