last line of file is duplicated using fscanf

Question

I am trying to print what is inside my history.txt file.

It works fine. The problem is the last part, it prints the last line twice.

example output:

abcd1234 12/31/2014 03:28:20 PM 5.00 0.00 // this will be printed twice
abcd1234 12/31/2014 03:28:20 PM 5.00 0.00 // here

here is the part where I used for reading and printing the file.

  while(!feof(fp))
        {
            fscanf(fp,"%s %s %s %s %f %f",code,hodate,hitime,distime,&deb1,&cre1);
            if(strcmp(code,x.accnum)==0)
            {
                if(strcmp(hodate,currentdate)==0)
                {
                    printf("%s\t%s\t%.2f\t%.2f\n",hodate,hitime,deb1,cre1);

                }
            }

        }

[`fscanf`](http://man7.org/linux/man-pages/man3/scanf.3.html) returns a value that indicates how many items were assigned. ***ALWAYS CHECK IT!*** There must be some example code that thinks it's okay to not check this return value. Beginners are apparently finding it because this happens several times every day. We must find this resource and destroy it! — Jonathon Reinhart, Dec 31 '14 at 07:50

score 4 · Accepted Answer · edited May 23 '17 at 12:28

4

Using feof() like this is wrong.

while (fscanf(hist, "%s %s %s %s %f %f", acR, hdate, htime, dis, &deb, &cre) == 6)
    {
    // Put your code here
    }

edited May 23 '17 at 12:28

Community

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1

answered Dec 31 '14 at 07:50

Gopi

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I'm really curious why two people down-voted this very sensible answer. – Jonathon Reinhart Dec 31 '14 at 07:53
@JonathonReinhart I really don't get it. And also it would be better for me also to learn if this is wrong – Gopi Dec 31 '14 at 07:54
1

Why the down-vote(s)? This is basically correct code. And the misuse of `feof()` is precisely why the last line is repeated. – Jonathan Leffler Dec 31 '14 at 07:54
@Jonathon: The question is a duplicate, and already has answers. It's not a good thing to answer such a question. – Thomas Padron-McCarthy Dec 31 '14 at 07:54
1

@ThomasPadron-McCarthy So you down vote? it which gives an impression that this answer is wrong – Gopi Dec 31 '14 at 07:55
2

@ThomasPadron-McCarthy: Nonsense! It is an excellent idea to leave a brief answer and let the duplicate explain itself fully. – Jonathan Leffler Dec 31 '14 at 07:55
@JonathanLeffler: Ok, I can buy that argument. (And the A part, even if it was a reply to a JonathOn!) – Thomas Padron-McCarthy Dec 31 '14 at 07:55
2

@ThomasPadron-McCarthy Just vote to close the question and move-along. No sense in punishing a perfectly succinct answer. – Jonathon Reinhart Dec 31 '14 at 07:56

last line of file is duplicated using fscanf

1 Answers1