ref: cde4b93a27af60da423b3ed387de5f7a31ba32b7
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; }