ref: 3579757291db68f8e17a376476454996b7961bd7
dir: /sys/src/ape/lib/ap/plan9/kill.c/
#include "lib.h" #include <fcntl.h> #include <unistd.h> #include <signal.h> #include <string.h> #include <stdio.h> #include <errno.h> static int note(int pid, char *msg, char *fmt) { int f; char pname[50]; sprintf(pname, fmt, pid); f = open(pname, O_WRONLY); if(f < 0){ errno = ESRCH; return -1; } if(msg != 0 && write(f, msg, strlen(msg)) < 0){ close(f); errno = EPERM; return -1; } close(f); return 0; } int kill(pid_t pid, int sig) { char *msg; int sid, r, mpid; if(sig == 0) msg = 0; else { msg = _sigstring(sig); if(msg == 0) { errno = EINVAL; return -1; } } if(pid < 0) { sid = getpgrp(); mpid = getpid(); if(setpgid(mpid, -pid) == 0) { r = note(mpid, msg, "/proc/%d/notepg"); setpgid(mpid, sid); } else { r = -1; } } else if(pid == 0) r = note(getpid(), msg, "/proc/%d/notepg"); else r = note(pid, msg, "/proc/%d/note"); return r; }