stdlib.h

   1 #include <stddef.h>
   2
   3 void *malloc(int n);
   4 void free(void *m);
   5
   6 int atoi(char *s);
   7 long atol(char *s);
   8 int abs(int n);
   9
  10 void exit(int status);
  11 char *getenv(char *name);
  12 void qsort(void *a, int n, int sz, int (*cmp)(void *, void *));