read from a file and display on monitor in reverse order

This is a discussion on read from a file and display on monitor in reverse order within the C++ Programming forums, part of the General Programming Boards category; works fine without the for loop.... if i use for loop...it doesnt give the output... where am i going wrong? ...

  1. #1
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    Aug 2013
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    read from a file and display on monitor in reverse order

    works fine without the for loop.... if i use for loop...it doesnt give the output... where am i going wrong?

    Code:
    #include<iostream>
    #include<conio.h>
    #include<fstream>
    using namespace std;
    main()
    {
    	char c;
    	int i;
    	ifstream in;
    	in.open("efg.txt");
    	int p=in.tellg();
    	for(i=1;i<p;i++)
    	{
    	in.seekg(-i,ios::end);
    		in>>c;
    		cout<<c;
    	}
    		in.close();
    		getch();
    		return 0;
    }

  2. #2
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    If by "works fine" you mean that it does nothing observable, then I suppose it works fine without the for loop. Your code has the same fundamental problem, with or without the loop, the only difference is whether there is a visible symptom.

    You need to open the input file in binary mode. The streaming operators (<< and >>) are also formatted I/O (i.e. not for binary mode).

    If the file isn't too large, it would be easier to read the entire file contents into memory, reverse them, and then output.
    Right 98% of the time, and don't care about the other 3%.

  3. #3
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    solved!

    Code:
    in.seekg(0,ios::end);
    just had to add this line!!!

  4. #4
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    You're just getting lucky. You're on a system where binary and text mode files happen to be equivalent.
    Right 98% of the time, and don't care about the other 3%.

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