Readfile不是从我的文本文件读取空白空间？ [英] Readfile is not reading the the blank spaces from my text file?

问题描述

我正在阅读一个文本文件，发现它不会打印字之间的空白字符。我想一次读取每个字符一个字符，然后将字符打印到输出窗口。读取将读取文件，但不显示空格，我无法找到为什么空白被跳过。

问题：为什么我的读取不会读取测试文件中的空白字符？

当我找到一个空白字符时， p>

代码：

  #includestdafx.h
 #includeiostream
＃include< iostream> 
＃include< fstream> 
 
 void readTestFile（）
 {
 char ch; 
 std :: fstream fin（C：/Users/itpr13266/Desktop/myTest.txt，std :: fstream :: in）; 
 while（fin>> ch）{
 std :: cout< Letter：<< ch < std :: endl; 
 if（ch ==''）<  - 应该捕获一个空格
 {
 std :: cout< 空白<< std :: endl; 
} 
 else<  - 只写写信
 {
 std :: cout< ch < std :: endl; 
} 
} 
} 
 
 int _tmain（int argc，_TCHAR * argv []）
 {
 readTestFile（）; 
 
 getchar（）; 
 return 0; 
} 
  

测试文件：

 这是为fprintf ...测试... 
这是测试fputs ... 
  

输出

  Letter：T 
 T 
 
h 
 ... etc ... 
  

解决方案>

标准输入函数 istream :: operator>>（）在执行输入之前跳过所有前导空格。如果您需要获取空格，可以使用以下几个选项：

• std :: noskipws

  
  
  

  通过设置 std :: ios_base :: noskipws 标志，流不会丢弃前导空格， ch 将给出每个连续字符的值。请注意，只有使用 char （ ch 会给出空格的值）的重载才能成功。对于任何其他数据类型，这将不起作用：

    while（fin>> std： ：noskipws>> ch）
   {
   // ... 
  } 
    




• std :: istream :: get（）

  
  
  

  get（）是一个UnformattedInputFunction函数，因此不会预先解析输入。

    while（fin.get（ch））
   {
   // ... 
  } 
    




• std :: istreambuf_iterator<>

  
  
  

  您还可以使用迭代器直接与缓冲区一起工作。 std :: istreambuf_iterator<> 也不解析输入：

    std :: copy（std :: istreambuf_iterator< char> {fin}，
   std :: istreambuf_iterator< char> {}，
   std :: ostreambuf_iterator< char> {std :: cout}，
    

I am reading in a text file and have found that it will not print the blank characters between the words. I want to read each character a character at a time and then print the character to the output window. The read will read the file but does not show the blank spaces and I have not been able to find out why the blank spaces are being skipped.

Question: Why is my read not reading the blank characters in my test file?

When i find a blank character I want to print the word Blank Space.

Code:

#include "stdafx.h"
#include "iostream"
#include<iostream>
#include<fstream>

void readTestFile()
{
    char ch;
    std::fstream fin("C:/Users/itpr13266/Desktop/myTest.txt", std::fstream::in);
    while (fin >> ch) {
        std::cout << "Letter: " << ch << std::endl;
          if (ch == ' ')  <-- should catch a blank spaces
          {
              std::cout << "Blank Space" << std::endl;
          }
          else  <-- Just write the letter
          {
              std::cout << ch << std::endl; 
          }
    }
}

int _tmain(int argc, _TCHAR* argv[])
{
   readTestFile();

   getchar();
   return 0;
}

Test File:

  This is testing for fprintf...
  This is testing for fputs...

Output

 Letter: T
 T
 Letter: h
 h
 ...etc...

解决方案

The standard input function istream::operator>>() skips all leading whitespace before performing input. If you need to obtain spaces, there are a couple options you can use:

• std::noskipws

  By setting the std::ios_base::noskipws flag, the stream will not discard leading whitespace and ch will be given the value of each consecutive character. Note that this succeeds only with the overload that takes a char (ch will be given the value of the space). For any other data type this will not work:

  while (fin >> std::noskipws >> ch)
  {
      // ...
  }
  

• std::istream::get()

  get() is an UnformattedInputFunction function, and thus will not parse the input beforehand.

  while (fin.get(ch))
  {
      // ...
  }
  

• std::istreambuf_iterator<>

  You can also use iterators to work directly with the buffer. std::istreambuf_iterator<> also doesn't parse the input:

  std::copy(std::istreambuf_iterator<char>{fin},
            std::istreambuf_iterator<char>{},
            std::ostreambuf_iterator<char>{std::cout},
  

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