1. We have moved from vBulletin to XenForo and you are viewing the site in the middle of the move. Though the functional aspect of everything is working fine, we are still working on other changes including the new design on Xenforo.
    Dismiss Notice

Reading from file and adding values to array

Discussion in 'C' started by srinivas@e-spec.net, Nov 20, 2007.

  1. srinivas@e-spec.net

    srinivas@e-spec.net New Member

    Reading from file and adding values to array

    I am new to the C/C++

    My Program:

    int main(int argc, _TCHAR* argv[])
    FILE *fp;
    char line[1000];
    char *CheckPoint[3000];
    //Opening a file and reading
    fp = fopen("C:\\config.txt","rt");
    while(fgets(line, 1000, fp) != NULL)
    char datatext[1000];
    sscanf (line, "%s", &datatext);
    printf ("%s\n", datatext);
    CheckPoint[i] = datatext;
    //Closing File
    return 0;
    //Config.txt Data


    My Question:

    I am able to read the data from the file from the above loop of reading the file
    but when i add it to the array the value incrementing the array and assiging it, the values gets changed

    first time from the txt file i get 10 and i add to CheckPoint = datatext; where initially i =0, the next loop when the value for the datatext = 20 the initial value get to 20 and also inserts 20 in the second place

    Where am i going wrong

    Please help me
    Last edited by a moderator: Nov 20, 2007
  2. shabbir

    shabbir Administrator Staff Member

    I don't see the i variable being declared as well as incremented and so I think your data is getting changed.
  3. Salem

    Salem New Member

    > CheckPoint = datatext;
    This is only a pointer, so when datatext is changed next time around the loop, then all the pointers to it will also appear to change as well.

    Make CheckPoint a true 2D array of chars, and use strcpy() to copy datatext.

    Or you might consider http://www.hmug.org/man/3/strdup.php, but that would not be a portable solution (although strdup is very easy to write yourself).
  4. srinivas@e-spec.net

    srinivas@e-spec.net New Member

    Thank You Shabbir & Salem

    Sorry to post a wrong code for not giving the initilizing the i variable as i have declared in my program

    strdup worked out

    Thank you once again

Share This Page