在C ++中的文件中的特定单词之后挤出单词 [英] Extarct a word after a particular word in a file in c++

问题描述

#include <fstream>
#include <iostream>
#include <string>

using namespace std;

int main()
  {
char word[30];
  string filename;
 //map<char,int> mymap;
  //map<char,int>::iterator it;


  
  cout << "Name your file> ";
  getline( cin, filename );

  fstream file( filename.c_str() );
  if (!file)
    {
    cout << "I could not open the file. Fooey.\n";
    return EXIT_FAILURE;
    }
  else 
  {
    string line;
    
    while (getline( file, line ))
      {
         if ( line.find("new") != string::npos)
    {
      if ( line.find("int *") != string::npos)
	  {
		//want to catch the pointer in which the memory is allocated  
	  }
    }

	 
     
      }
    file.close();
    }

  return EXIT_SUCCESS;
  }

我正在创建一个静态分析器以检测内存泄漏..请帮助

I am creating a static analyzer to detect memory leaks ..please help

推荐答案

我认为使用Regular Expressions可以帮助您完成此项目:

http://linuxgazette.net/issue27/mueller.html [ Henry Spencer的Regexp引擎已重新访问 [ http://www.regular-expressions.info/tutorial.html [

I think using Regular Expressions will help you a lot in doing this project :

http://linuxgazette.net/issue27/mueller.html[^]

Henry Spencer''s Regexp Engine Revisited[^]

http://www.regular-expressions.info/tutorial.html[^]

There are many C++ libraries for Regular Expression pattern matching. Use google to find more resources about it.

您还可以使用对line.find()的调用的返回值，该返回值给出了字符串的起始位置.但是，您的代码作为分析器存在一个主要问题，因为并非每个人都使用相同的约定来编写代码.考虑以下代码行:

You could also use the return value of the call to line.find() which gives the starting position of the string. However your code has a major problem as an analyzer in that not everyone writes using the same conventions. consider the following lines of code:

int *pOne;
int* pTwo;
int  *    // this is a comment
  pThree;

所有这些在语法上都是正确的，但是您还需要更多才能识别它们.

All of these are syntactically correct but you need quite a lot more to be able to recognise them.

是的，您是对的...这就是为什么我这样做来提取变量名. ..

yes you are right...that is why i did thi to extract the variable name...

  while (getline( file, line ))
    {
       if ( line.find("new") != string::npos)
        {
      temp = line;
      string::iterator It = temp.begin();
while ( *It != '*'  )
  {
      It++;
  }
    It++;
   while ( *It != '='  )
  {

      word = *It;
      It++;
     if (word ==' ')
     {
         continue;

     }

      str = str + word;
   }

但是如果声明是这样的话:

but again if the declaration is like this:

int* p ;
p = new int;

问题仍然存在..你能帮我一下吗

the problem still persists..can you help plzzz

这篇关于在C ++中的文件中的特定单词之后挤出单词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！