reading content of .txt file int oa 2d array

This is a discussion on reading content of .txt file int oa 2d array within the C Programming forums, part of the General Programming Boards category; Hello everyone, I have a 'simple' and quick question. I want to read .txt file and copy the content into ...

  1. #1
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    reading content of .txt file int oa 2d array

    Hello everyone,

    I have a 'simple' and quick question. I want to read .txt file and copy the content into a 2d array for further processing in my program.

    Let's say i have a 5 by 5 integer array saved in .txt format.

    Could you please send me a simple example/template which could solve my problem?


    Thanks,

    Joealem.

  2. #2
    Jack of many languages Dino's Avatar
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    Please check the FAQ for examples of code.
    Mac and Windows cross platform programmer. Ruby lover.

    Quote of the Day
    12/20: Mario F.:I never was, am not, and never will be, one to shut up in the face of something I think is fundamentally wrong.

    Amen brother!

  3. #3
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    Thanks Dino for quick reply. I search my question in FAQ but i cant find a specific answer to my problem. Could you please write a simple example? or send me the link of the FAQ or any other info.

    Thanks again,

    Joealem

  4. #4
    ATH0 quzah's Avatar
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    We're not here to do everything for you. Post your attempt, what you're stuck on, etc., and we'll point you in the right direction. I also find it extremely hard to believe that there are zero search results on this forum for people working with 2D arrays and reading from files.

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

  5. #5
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    Code:
    #include<stdio.h>
    #include<stdlib.h>
    #include<math.h>
    
    
    int main()
    {
    	int i,j,it=7,nz=5,nx=5;
    	
    	int P[nz][nx];
    	int x[nz][nx];
    	
    	
    	char filename[20];
    	
    	sprintf(filename,"SF_%d.txt", it);
    	FILE *file;
    	file = fopen(filename, "w" );
    	
    	for (i=0; i<nz; i++) 
    	{
    		for (j=0; j<nx; j++) 
    		{
    			P[i][j]=i*i;
    		}
    	}
    	
    	for(i=0;i<nz;i++)
    	{
    		for(j=0;j<nx;j++)
    		{
    			fprintf(file,"%d\t",P[i][j]);
    		}
    		fprintf(file,"\n");
    	}
    	
    	FILE *hFile;
    	char filename2[20];
    	sprintf(filename2,"SF_%d.txt",it);
    	hFile = fopen("SF_7.txt", "r");
    	
    	
    		for(i=0;i<nz;i++)  
    		{
    			for(j = 0; j < nx; j++)  
    			{
    				fscanf(hFile,"%d\t", &x[i][j]);
    			}
    		}
    	
    
    		for (i=0; i<nz; i++) 
    		{
    		for (j=0; j<nx; j++) 
    		{
    		printf("%d\t",x[i][j]);
    		}
    		printf("\n");
    		}
    	return 0;
    	
    }
    Out put: SF_7.txt and

    0 8 -1881015350 -1881017180 -1073743808
    3 48 44 1287 0
    0 1 -1880731168 3260 -1073743848
    3 -1881144184 -1880955984 -1073743736 -1881029853
    -1073743808 3 48 -1073743792 1287


    which is 5 by 5 matrix displayed after reading the file SF_7.txt. I don't understand why i am getting this result. The expected result is

    0 0 0 0 0
    1 1 1 1 1
    4 4 4 4 4
    9 9 9 9 9
    16 16 16 16 16

    Please give me your comments.

    Thanks,

    Joealem.

  6. #6
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    Please forward me some comments....
    thanks,

    Joealem

  7. #7
    ATH0 quzah's Avatar
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    Code:
    FILE *hFile;
    	char filename2[20];
    	sprintf(filename2,"SF_%d.txt",it);
    	hFile = fopen("SF_7.txt", "r");
    Why do you have this block in there twice? Looks like you got a bit too excited with the copy-paste there.

    I'm not sure why you aren't just reusing the name that you've already set up earlier. Anyway, you never fclose your file after writing to it, before you try opening it again to read it.


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

  8. #8
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    Quote Originally Posted by quzah View Post
    Code:
    FILE *hFile;
    	char filename2[20];
    	sprintf(filename2,"SF_%d.txt",it);
    	hFile = fopen("SF_7.txt", "r");
    Why do you have this block in there twice? Looks like you got a bit too excited with the copy-paste there.

    I'm not sure why you aren't just reusing the name that you've already set up earlier. Anyway, you never fclose your file after writing to it, before you try opening it again to read it.


    Quzah.

    Code:
    .......
     fclose(file)
    ......
    It works. Thank you so much!

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