sscanf无法读取双十六进制 [英] sscanf fails to read double hex

问题描述

我需要在文本文件中保留具有其他ascii值的某些双精度数的确切二进制表示形式，因此我正在使用

I need to preserve the exact binary representation of some doubles in a text file with other ascii values, so I am using "%a" as suggested in this question.

fprintf (pFile, "Scale: %a, %a, %a\n", scale.x, scale.y, scale.z);

但是，当我尝试用％la"读取时，scanf返回读取的0项.

However, when I try to read it in with "%la" the scanf returns 0 items read.

double x=0, y=0, z=0;
fgets(buf, sizeof buf, pFile);
int test = sscanf (buf, "Scale: %la, %la, %la\n", &x, &y, &z);
// test is zero!

打开调试器时，我看到字符串缓冲区与我期望的完全一样.

When I open up the debugger, I see that the string buffer is exactly as I expected it.

buf ...比例尺:0x1.fc70e3p-1、0x1.fc70e3p-1、0x1.fc70e3p-1 \ n" ... 字符[1000]

buf ... "Scale: 0x1.fc70e3p-1, 0x1.fc70e3p-1, 0x1.fc70e3p-1\n" ... char[1000]

那它为什么不读呢?

根据 Nate Eldredge 的要求，这是我的MCVE版本:

As requested by Nate Eldredge, here is my MCVE version:

#include <stdio.h>
int main(int argc, char *argv[])
{
    double x=0, y=0, z=0;
    const char* buf = "Scale: 0x1.fc70e3p-1, 0x1.fc70e3p-1, 0x1.fc70e3p-1\n";
    int test = sscanf(buf, "Scale: %la , %la , %la", &x, &y, &z);
    // test is zero!
}

注意:我正在使用MS Visual Studio 2013

Note: I am using MS Visual Studio 2013

第二注:我需要将源代码和数据文件发送给第三方，后者拥有自己的编译器.因此，保存格式必须相对独立于平台.

Second Note: I need to send the source code and data files to a third party, who has his own compiler. So the save format has to be relatively platform-independent.

推荐答案

Microsoft VS2013 strtod，sscanf和istringstream等，未未实现c99 c ++ 11标准，并且它们无法解析十六进制浮点数或十六进制双精度点.

Microsoft VS2013 strtod, sscanf, and istringstream, etc. did not implement the c99 c++11 standard and they cannot parse hex floats or hex doubles.

• 相关的错误报告:

• Related Bug Report:

https://github.com/JuliaLang/julia/issues/6349

这篇关于sscanf无法读取双十六进制的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！