#include #include #include "ourhdr.h" int main(void) { struct stat statbuf; /* turn on set-group-ID and turn off group-execute */ if (stat("foo", &statbuf) < 0) err_sys("stat error for foo"); if (chmod("foo", (statbuf.st_mode & ~S_IXGRP) | S_ISGID) < 0) err_sys("chmod error for foo"); /* set absolute mode to "rw-r--r--" */ if (chmod("bar", S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH) < 0) err_sys("chmod error for bar"); exit(0); }