Thread: reading the number of characters in a file

Hello everybody, I am having a problema with a simple program that is supposed to find the number of characters in a file but apparently it gives me n+1 elements instead of just n. Here is the code, hope you can help me.

Code:

#include <stdio.h>
int main (void)
{
FILE *fp;
char c;
int d=0;
fp=fopen("ex4.txt","r");
while(c!=EOF)
{
c=fgetc(fp);
d=d+1;
}
fclose(fp);
printf("The number of characters is %d\n",d);


return 0;
}

The problem is probably your while condition. Using EOF to control an input loop usually leads to an extra extraction. Why not use the actual read to control the read loop?

You also need to find and use some kind of indentation style, it'll make reading your program much easier.


Jim

Hello, thank you for your answer, I'll try to make my code readable next time. How can i make that while you're talking of? I cannot find the solution here...

In C, you do not whether you are at the end of a file (or any input stream), until you try to read past the end.

Think about the above sentence, until you understand its implications.

Originally Posted by khanny

Code:

    while (c != EOF) {
        c = fgetc(fp);
        d = d+1;
    }

The above loop detects the end of file at the second line, when fgetc(fp) returns EOF.

That EOF is not a character -- it is not "the last character in the file", or even an end-of-file character; it is just a special value that many read functions, including fgetc() , return when they detect that there is no more input.

(I guess it is okay to think of it as end of file mark, but just remember that it is not actually saved in the file or file system, nor does it describe any real character at all; it is just a synthetic value the C library provides you as a notification for the end-of-input case.)

Now, consider this: Does your above loop count c == EOF as a character in the file?