Dynamic memory allocation for file handling

This is a discussion on Dynamic memory allocation for file handling within the C Programming forums, part of the General Programming Boards category; Hi I am processing soem text files in C using dyanmic memory allocation where I need to compare 2 files ...

  1. #1
    Registered User
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    Nov 2002
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    Dynamic memory allocation for file handling

    Hi

    I am processing soem text files in C using dyanmic memory allocation where I need to compare 2 files with 100000 records.
    the code is

    FILE *f;
    char s[10],s1[10];
    char a[LIMIT][10],a1[LIMIT][10];//LIMIT = 100000

    int x=0,y,i=0,j=0,k,i_sec=0,j_sec=0,k_sec,k_comp,l_com p,q;

    //master.txt is the masterfile.Ex: G11

    f=(FILE *)malloc(100000);

    f=fopen("C:/WIN95/Desktop/master.txt","r");

    if (!f)
    return 1;

    while ((fgets(s,11,f)!= NULL) && (i < LIMIT)) //fgets reads a string from the file
    {

    strcpy(a[i],s);
    //printf("% d ---- %s\n",i,a[i]);
    ++i;
    }

    k=i;

    //printf("k= %d",k);

    free(f);
    fclose(f);

    But I get a memeory error; perhaps exceeding the heap allocation.

    I will be very thankful if you can help me here.
    Last edited by prashanth_sh; 11-07-2002 at 05:23 AM.

  2. #2
    ATH0 quzah's Avatar
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    f=(FILE *)malloc(sizeof(FILE));
    What the hell are you doing? You don't allocate space for file pointers. Furthermore, don't typecast your malloc returns. This isn't C++ so there's no point in ever doing so.

    Quzah.
    Hope is the first step on the road to disappointment.

  3. #3
    Me want cookie! Monster's Avatar
    Join Date
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    Code:
    while ((fgets(s,11,f)!= NULL)
    Buffer overflow, you have only space for 10 characters. Change it to:
    Code:
    while ((fgets(s,10,f)!= NULL)

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