ref: f777743b7242e539a8ac806e4e15c4b527be4bb6
dir: /sys/src/libc/9sys/getppid.c/
#include <u.h> #include <libc.h> int getppid(void) { char b[20]; int f; memset(b, 0, sizeof(b)); f = open("/dev/ppid", 0); if(f >= 0) { read(f, b, sizeof(b)); close(f); } return atol(b); }