命令提示符关闭而不接受输入

Question

Why am I not being able to enter anything? The program on running doesn't wait for my input and the cmd prints Enter a Filename and closes. I am executing it on Visual Studio 2008.

int main(int argc, char* argv[])
    {
        if(argc<2)
            printf("\nEnter a filename");
        else
        { 
            //code
        }
        getch();
        return 0;
        }

What am I doing wrong?

Answer 1

I'm guessing something is in the buffer. Try seeing what it is?

int main(int argc, char* argv[])
{
    if(argc<2)
        printf("\nEnter a filename");
    else
    { 
        //code
    }

    while (true)
    {
        int c;
        c = getch();
        printf( ": %d\n", c );
    }
    return 0;
 }

After your response it appears there is the letter b in your input stream when your program is called. Not sure how to explain that. Are you trying to get a whole string and not just a character?

int main(int argc, char* argv[])
{
    char string [256];
    if(argc<2)
    {
        printf("Enter a filename:");
        gets (string);
    }
    else
    { 
        //assign string to argv[1]
    }


   printf ("Your filename is: %s\n",string);
   return 0;
  }

Answer 2

You should usually end, not start, the outputted string with newline (because on stdout a newline may flush buffers). Or you should call fflush(stdout); before your call to getch() . So try with printf("Enter a filename:\\n");

Answer 3

Try running your program without debugging ( Ctrl+F5 in Visual Studio). This will keep the cmd window open after the program has finished.

(edit)Perhaps you want to do something like this:

int main(int argc, char* argv[])
    {
        string filename;
        if(argc<2)
        {
            printf("\nEnter a filename");
            cin >> filename;
        }
        else
        { 
            //code
        }
        // getch(); // Use Ctrl+F5 instead
        return 0;
    }

getch() only gets 1 char from input stream.