任何方式来摆脱空字符在结尾的istream得到？ [英] Any way to get rid of the null character at the end of an istream get?

问题描述

我目前正试图写一点代码来读取一个文件，并提取它的位并将其保存为变量。

这里是相关的代码： / p>

 字节地址[10]; 
 
 ifstream tracefile; 
 tracefile.open（trace.txt）; 
 tracefile.seekg（2，ios :: beg）; 
 tracefile.get（address，10，''）; 
 cout<地址; 
  

文件内容:(只是第一行）

  R 0x00000000 
  

m有地址错过最后的'0'，因为它在那里放一个/ 0字符，我不知道如何解决这个问题？所以它输出：

  0x0000000 
  

$ b b

我也有问题

  tracefile.seekg（2，ios :: cur） ; 
  

它似乎不工作，因此为什么我把它改为ios :: beg尝试和得到一些工作，虽然显然，一旦我尝试阅读多行之后，将无法使用。

任何帮助将不胜感激。 >

解决方案

ifstream :: get（） 将尝试生成一个以null结尾的C字符串，但是没有为其提供足够的空间。

您可以：

1. 分配 ; （或更大）以容纳长度超过9个字符的以null结尾的字符串。


2. 使用 ifstream :: read（）




如果您想要一个可以动态计算行长度的缓冲区，请使用 std :: getline 与 std :: string 。

  std :: string buffer; 
 tracefile.seekg（2，ios :: beg）; 
 std :: getline（tracefile，buffer）; 
   
 
 
 
 编辑2  
 
 
 
如果只想读取下一个空格，请使用：
  std :: string buffer; 
 tracefile.seekg（2，ios :: beg）; 
 tracefile>>缓冲; 
  
 
I'm currently trying to write a bit of code to read a file and extract bits of it and save them as variables.

Here's the relevant code:
char address[10];

ifstream tracefile;
tracefile.open ("trace.txt");
tracefile.seekg(2, ios::beg);
tracefile.get(address, 10, ' ');
cout << address;
The contents of the file: (just the first line)
R 0x00000000
The issue I'm having is that address misses the final '0' because it puts a /0 character there, and I'm not sure how to get around that? So it outputs:
0x0000000
I'm also having issues with 
tracefile.seekg(2, ios::cur);
It doesn't seem to work, hence why I've changed it to ios::beg just to try and get something work, although obviously that won't be useable once I try to read multiple lines after one another.

Any help would be appreciated.
解决方案
ifstream::get() will attempt to produce a null-terminated C string, which you haven't provided enough space for.

You can either:

Allocate char address[11]; (or bigger) to hold a null-terminated string longer than 9 characters.
Use ifstream::read() instead to read the 10 bytes without a null-terminator.
Edit:

If you want a buffer that can dynamically account for the length of the line, use std::getline with a std::string.
std::string buffer;
tracefile.seekg(2, ios::beg);
std::getline( tracefile, buffer );
Edit 2

If you only want to read to the next whitespace, use:
std::string buffer;
tracefile.seekg(2, ios::beg);
tracefile >> buffer;


                        
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