ifstream error message

This is a discussion on ifstream error message within the C++ Programming forums, part of the General Programming Boards category; I am attempting to read a filename from the user and then open the file, however, if I press enter ...

  1. #1
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    ifstream error message

    I am attempting to read a filename from the user and then open the file, however,
    if I press enter instead of typing a filename I get an error from the compiler:

    #######################
    Debug Assertion Failed!
    ...
    Expression: *file != _T('\0')
    ...
    #######################

    It works unless the user presses enter without typing a filename, here is the code:

    string filename;
    getline (cin, filename);
    ifstream fin(filename.c_str());


    Visual C++.NET
    Windows XP


    THANKS!

  2. #2
    Registered User
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    One possible solution is to make sure string filename contains the filename and is not empty.

    Kuphryn

  3. #3
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    How can i test whether the string is empty or not.

    Also...if i put my 'ifstream fin(filename.c_str());' inside an 'if' statement, all other references to 'fin' generate errors because it is an undeclared identifier

    Thanks,

    quizkiwi

  4. #4
    Code Goddess Prelude's Avatar
    Join Date
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    >How can i test whether the string is empty or not.
    Code:
    #include <iostream>
    #include <string>
    
    int main()
    {
      std::string filename;
    
      std::getline ( std::cin, filename );
      
      if ( !filename.empty() )
        std::cout<< filename <<std::endl;
      else
        std::cerr<<"You must enter a filename"<<std::endl;
    }
    >if i put my 'ifstream fin(filename.c_str());' inside an 'if' statement, all other references to 'fin' generate errors
    So don't do that.
    My best code is written with the delete key.

  5. #5
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    Thanks, that works good!

    ->"Crushing dreams at the speed of sarcasm." ....my kinda person!

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