Problem in reading datafile

[rsk]

Hi Friends,

I have the following code which reads the hexadecimal data from the
"data.txt" file into the arrays.

But when i run this code it is reading some garbage data after reading all
the data.

--------------------------------------------------

The data.txt file contains the data as:
11111111
22222222
33333333
44444444
55555555
66666666
77777777
88888888
99999999
aaaaaaaa
--------------------------------------------------

The code is as follows:

#include <stdio.h>
#include <math.h>

main ()
{
FILE *fdataptr ;
int data_count ;
int data [30] ;
int source0 [31] ;
int source1 [31] ;
int source2 [31] ;
int source3 [31] ;
int source4 [31] ;
int a ;
int b ;
int c ;
int d ;
int e ;
data_count =0;
a=0;
b=0;
c=0;
d=0;
e=0;
// Open the file containing data
fdataptr = fopen("data.txt ", "r");
if(fdataptr==NU LL){
printf("\n Cannot open data.txt file.\n");
exit(1);
}
else {
printf("\n data.txt File is Opened Sucessfully.\n" );

while(!feof(fda taptr)) {
fscanf(fdataptr ,"%x", &source0[a]);
data_count++;
printf("\n Data count is %d", data_count);
printf("\n Source0 [%d] stream data is %x\n",a,source0[a]);

fscanf(fdataptr ,"%x", &source1[b]);
data_count++;
printf("\n Data count is %d", data_count);
printf("\n Source1 [%d] stream data is %x\n",b,source1[b]);

fscanf(fdataptr ,"%x", &source2[c]);
data_count++;
printf("\n Data count is %d", data_count);
printf("\n Source2 [%d] stream data is %x\n",c,source2[c]);

fscanf(fdataptr ,"%x", &source3[d]);
data_count++;
printf("\n Data count is %d", data_count);
printf("\n Source3 [%d] stream data is %x\n",d,source3[d]);

fscanf(fdataptr ,"%x", &source4[e]);
data_count++;
printf("\n Data count is %d", data_count);
printf("\n Source4 [%d] stream data is %x\n",e,source4[e]);

a++;
b++;
c++;
d++;
e++;

}//close of while
}//close of else
}//close of main

-------------------------------------------------

I got the output as

data.txt File is Opened Sucessfully.

Data count is 1
Source0 [0] stream data is 11111111

Data count is 2
Source1 [0] stream data is 22222222

Data count is 3
Source2 [0] stream data is 33333333

Data count is 4
Source3 [0] stream data is 44444444

Data count is 5
Source4 [0] stream data is 55555555

Data count is 6
Source0 [1] stream data is 66666666

Data count is 7
Source1 [1] stream data is 77777777

Data count is 8
Source2 [1] stream data is 88888888

Data count is 9
Source3 [1] stream data is 99999999

Data count is 10
Source4 [1] stream data is aaaaaaaa

Data count is 11
Source0 [2] stream data is 0

Data count is 12
Source1 [2] stream data is 0

Data count is 13
Source2 [2] stream data is 0

Data count is 14
Source3 [2] stream data is 40002233

Data count is 15
Source4 [2] stream data is 0
Can you please tell me why iam getting the values
0,0,0,40002233 and 0 which are not available in the data.txt file.
Thanks in advance.
Rsk...

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[Mark Bluemel]

rsk wrote:
....

while(!feof(fda taptr)) {
fscanf(fdataptr ,"%x", &source0[a]);
data_count++;
printf("\n Data count is %d", data_count);
printf("\n Source0 [%d] stream data is %x\n",a,source0[a]);

I suggest you read the FAQ (http://c-faq.com), especially the section on
IO. This should help you understand why your loop control is mistaken.

[John Gordon]

In <f0************ *************** ***@localhost.t alkaboutprogram ming.com"rsk" <kr******@yahoo .co.inwrites:

But when i run this code it is reading some garbage data after reading all
the data.

while(!feof(fda taptr)) {
fscanf(fdataptr ,"%x", &source0[a]);

This is why.

feof() is not true until you've attempted to read *past* end-of-file.

If there are ten lines in the file and you've done ten fscanf()s you
have not reached end-of-file yet, and thus feof() will not return true.

End-of-file will only trigger once you attempt the eleventh fscanf().

--
John Gordon A is for Amy, who fell down the stairs
go****@panix.co m B is for Basil, assaulted by bears
-- Edward Gorey, "The Gashlycrumb Tinies"

[Chris Dollin]

rsk wrote:

I have the following code which reads the hexadecimal data from the
"data.txt" file into the arrays.

I'm not going to answer your question (because I see others have done
that); I'm going to make a comment about your code.

Ugh.
When I see:

int source0 [31] ;
int source1 [31] ;
int source2 [31] ;
int source3 [31] ;
int source4 [31] ;
int a ;
int b ;
int c ;
int d ;
int e ;

(and ignoring that you don't take the opportunity to initialise your
variables /right there/), and:

fscanf(fdataptr ,"%x", &source0[a]);
data_count++;
printf("\n Data count is %d", data_count);
printf("\n Source0 [%d] stream data is %x\n",a,source0[a]);

fscanf(fdataptr ,"%x", &source1[b]);
data_count++;
printf("\n Data count is %d", data_count);
printf("\n Source1 [%d] stream data is %x\n",b,source1[b]);

fscanf(fdataptr ,"%x", &source2[c]);
data_count++;
printf("\n Data count is %d", data_count);
printf("\n Source2 [%d] stream data is %x\n",c,source2[c]);

fscanf(fdataptr ,"%x", &source3[d]);
data_count++;
printf("\n Data count is %d", data_count);
printf("\n Source3 [%d] stream data is %x\n",d,source3[d]);

fscanf(fdataptr ,"%x", &source4[e]);
data_count++;
printf("\n Data count is %d", data_count);
printf("\n Source4 [%d] stream data is %x\n",e,source4[e]);

a++;
b++;
c++;
d++;
e++;

I shudder. Why, why, why is essentially /the same code/ being repeated
over and over and over again again? That blocklet could quite tidily
be turned into a function, and your code would be shorter and clearer
for it.

And you'd probably end up reducing the number of variables by a factor
of five, too.

--
Chris "win-win" Dollin

Hewlett-Packard Limited registered office: Cain Road, Bracknell,
registered no: 690597 England Berks RG12 1HN