hidden size_t __stdio_read(FILE *, unsigned char *, size_t);
hidden size_t __stdio_write(FILE *, const unsigned char *, size_t);
hidden size_t __stdout_write(FILE *, const unsigned char *, size_t);
hidden size_t __stdio_read(FILE *, unsigned char *, size_t);
hidden size_t __stdio_write(FILE *, const unsigned char *, size_t);
hidden size_t __stdout_write(FILE *, const unsigned char *, size_t);