-void failed_assert(char *a, char *file, int line);
-void swap(void **p1, void **p2);
+extern void failed_assert(char *a, char *file, int line);
+void pipe_spawn(char *buf, unsigned int len, Display *dpy, const char *cmd);
+extern void spawn(Display *dpy, const char *cmd);
+extern void swap(void **p1, void **p2);
+unsigned char *getselection(unsigned long offset, unsigned long *len, unsigned long *remain);