txt files

This is a discussion on txt files within the C++ Programming forums, part of the General Programming Boards category; Hi, When writing my last program i ran into a problem: when writing to text file i want my program ...

  1. #1
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    txt files

    Hi,
    When writing my last program i ran into a problem: when writing to text file i want my program to add the data to file, not replace it (I mean like data field 1, data field 2. data field 1 again and data field 2 again with different values offcource)

  2. #2
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    Code:
    ofstream file("filenamt.txt", ios::app);
    if your using standard C++ and if you are not using std as a global namespace

    then that will be std::ios::app instead.

    also, if this is not the problem.. post the source code so we can see what the problem is

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    You must open the file for appending.I.e. if you use fopen(), you must specify "a" in the mode.

    Or if you want to insert data in the midle of the file, you must first shift the data and the to replace the data, which is stored in then place.

    P.S. Sorry if my English is not good. I just saw that I have did my post at the same time as another post. I think that they complement eatch other.
    Last edited by Gravedigga; 08-04-2004 at 01:52 PM.

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    Thanx, got it now

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    Sorry for double post, but i have unother problem. I want my program to get random values from that file (meaning randomly togeather value 1 and value 2, then again random value 1 and random value 2)

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    create a container to hold the file contents. Read the entire file into the container. randomly access the data in the container. OR, if you have perfectly symetrical data in the file--for example value1 and value2 are always have the same memory footprint and there is nothing else in the file, then you can use fseek() to place the file pointer wherever desired to access just the desired value.

    Edit: by memory footprint I mean that value1 and value2 are both ints or value1 is a double and value2 is an float or something like that. With strings, the memory footprint will only be the same if the strings written to file always have the same number of char and are therefore of predicatable, stable sizes.
    Last edited by elad; 08-06-2004 at 02:54 PM.

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    Thanx, ill try the fseek(), but I dont have any idea, what do you mean under container =D (ya, i know im just unother noob taking projects, what i cant handle:P)

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    container is just generic verbage for any object that can hold a group of other objects. An array is a container, a list is a container, a queue is a container, a stack is a container, etc.

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    Oh, ok thank you again =)

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