-# ifdef STDC_HEADERS
-# include <stdlib.h>
-# include <string.h>
-# else /* no standard C headers */
- extern char *getenv (const char *);
- extern char *strcpy (char *, const char *);
- extern char *strncpy (char *, const char *, unsigned long);
- extern char *strcat (char *, const char *);
- extern char *strncat (char *, const char *, unsigned long);
- extern int strcmp (const char *, const char *);
- extern int strncmp (const char *, const char *, unsigned long);
- extern int system (const char *);
- extern unsigned long strlen (const char *);
- extern void *malloc (unsigned long);
- extern void *realloc (void *, unsigned long);
- extern void exit (int);
- extern void free (void *);
- extern void *memmove (void *, const void *, unsigned long);
-# define EXIT_SUCCESS 0
-# define EXIT_FAILURE 1
-# endif