-extern int system PARAMS ((const char *));
-
-static int os_init PARAMS ((host_callback *));
-static int os_shutdown PARAMS ((host_callback *));
-static int os_unlink PARAMS ((host_callback *, const char *));
-static long os_time PARAMS ((host_callback *, long *));
-static int os_system PARAMS ((host_callback *, const char *));
-static int os_rename PARAMS ((host_callback *, const char *, const char *));
-static int os_write_stdout PARAMS ((host_callback *, const char *, int));
-static void os_flush_stdout PARAMS ((host_callback *));
-static int os_write_stderr PARAMS ((host_callback *, const char *, int));
-static void os_flush_stderr PARAMS ((host_callback *));
-static int os_write PARAMS ((host_callback *, int, const char *, int));
-static int os_read_stdin PARAMS ((host_callback *, char *, int));
-static int os_read PARAMS ((host_callback *, int, char *, int));
-static int os_open PARAMS ((host_callback *, const char *, int));
-static int os_lseek PARAMS ((host_callback *, int, long, int));
-static int os_isatty PARAMS ((host_callback *, int));
-static int os_get_errno PARAMS ((host_callback *));
-static int os_close PARAMS ((host_callback *, int));
-static void os_vprintf_filtered PARAMS ((host_callback *, const char *, va_list));
-static void os_evprintf_filtered PARAMS ((host_callback *, const char *, va_list));
-static void os_error PARAMS ((host_callback *, const char *, ...))
-#ifdef __GNUC__
- __attribute__ ((__noreturn__))
-#endif
- ;
-static int fdmap PARAMS ((host_callback *, int));
-static int fdbad PARAMS ((host_callback *, int));
-static int wrap PARAMS ((host_callback *, int));
-