versions

绝对正真的stdio.h的实现

libc {
  GLIBC_2.0 {
    # global variables
    _sys_errlist; _sys_nerr; _sys_siglist;

    # functions used in other libraries
    __printf_fp; __vfscanf;

    # variables in normal name space
    sys_errlist; sys_nerr; sys_sigabbrev; sys_siglist;

    # a*
    asprintf;

    # c*
    ctermid; cuserid;

    # d*
    dprintf;

    # f*
    flockfile; fprintf; fscanf; ftrylockfile; funlockfile;

    # g*
    getline; getw;

    # p*
    parse_printf_format; perror; printf; putw;

    # r*
    register_printf_function; remove; rename;

    # s*
    scanf; snprintf; sprintf; sscanf;

    # t*
    tempnam; tmpfile; tmpnam; tmpnam_r;

    # v*
    vfprintf; vfscanf; vprintf; 
  }
  GLIBC_2.1 {
    # p*
    printf_size; printf_size_info;

    # t*
    tmpfile; tmpfile64;
  }
  GLIBC_PRIVATE {
    # global variables
    _itoa_lower_digits;
}