ref: e20dba2c5407ca584da6a70c2b35650452abf3c1
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) { return write(ctl, "hangup", sizeof("hangup")-1) != sizeof("hangup")-1; }