setxferbuf
{ "rcvbuf", H(xferbufhelp), 0, 0, 0, CMPL0 setxferbuf },
{ "sndbuf", H(xferbufhelp), 0, 0, 0, CMPL0 setxferbuf },
{ "xferbuf", H(xferbufhelp), 0, 0, 0, CMPL0 setxferbuf },
void setxferbuf(int, char **);