-extern void error(char *errstr, ...);
-extern void *emallocz(unsigned int size);
-extern void *emalloc(unsigned int size);
-extern void *erealloc(void *ptr, unsigned int size);
-extern char *estrdup(const char *str);
-#define eassert(a) do { \
- if(!(a)) \
- failed_assert(#a, __FILE__, __LINE__); \
- } while (0)
-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);
+#define MAX(A, B) ((A) > (B) ? (A) : (B))
+#define MIN(A, B) ((A) < (B) ? (A) : (B))
+#define BETWEEN(X, A, B) ((A) <= (X) && (X) <= (B))
+
+void die(const char *fmt, ...);
+void *ecalloc(size_t nmemb, size_t size);