sigchain.hon commit ls-files -k: a directory only can be killed if the index has a non-directory (2eac2a4)
   1#ifndef SIGCHAIN_H
   2#define SIGCHAIN_H
   3
   4typedef void (*sigchain_fun)(int);
   5
   6int sigchain_push(int sig, sigchain_fun f);
   7int sigchain_pop(int sig);
   8
   9void sigchain_push_common(sigchain_fun f);
  10
  11#endif /* SIGCHAIN_H */