ref: 3f5db0b7f757a6ccbfe2d22a8bab67d27dd9235c
dir: /sys/src/ape/lib/ap/plan9/getppid.c/
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include "sys9.h"
pid_t
getppid(void)
{
char buf[32];
int f;
snprintf(buf, sizeof(buf), "/proc/%d/ppid", getpid());
f = open(buf, 0);
if(f < 0)
return 0;
memset(buf, 0, sizeof(buf));
read(f, buf, sizeof(buf)-1);
close(f);
return atol(buf);
}