ref: f3285bceba6a6f2d50a85c98b226caf1ff7265b9
dir: /sys/src/libc/port/hangup.c/
#include <u.h> #include <libc.h> #include <ctype.h> /* * force a connection to hangup */ int hangup(int ctl) { static char msg[] = "hangup"; return write(ctl, msg, sizeof(msg)-1) != sizeof(msg)-1; }