1 #include <sys/types.h> 2 #include <sys/stat.h> 3 #include <fcntl.h> 4 #include <stdlib.h> 5 #include <unistd.h> 6 #include <errno.h> 7 #include "sys9.h" 8 9 pid_t 10 getppid(void) 11 { 12 int n, f; 13 char ppidbuf[15]; 14 15 f = open("#c/ppid", 0); 16 n = read(f, ppidbuf, sizeof ppidbuf); 17 if(n < 0) 18 errno = EINVAL; 19 else 20 n = atoi(ppidbuf); 21 close(f); 22 return n; 23 } 24