Thread: 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.

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

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.

Please forward me some comments....
thanks,

Joealem

Originally Posted by quzah

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!