ref: 1e8c6d3d412ce472d3173a78e285697b71803fb5
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); }