ref: 3223acae34b67330351ac8071c35ff9f77ee5b83
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; }