Question

I’m using fgets with stdin to read in some data, with the max length I read in being 25. With one of the tests I’m running on this code, there are a few hundred spaces after the data that I want – which causes the program to fail.

Can someone advise me as to how to ignore all of these extra spaces when using fgets and go to the next line?

Answer 1

Use fgets() iteratively, then scan the string to see whether it is all spaces (and whether it ends with a newline) and ignore it if it is. Or use getc() or getchar() in a loop instead?

char buffer[26];

while (fgets(buffer, sizeof(buffer), stdin) != 0)
{
    ...process the first 25 characters...
    int c;
    while ((c = getchar()) != EOF && c != '\n')
        ;
}

That code simply ignores all characters up to the next newline. If you want to ensure that they are spaces, add a test in the (inner) loop – but you have to decide what to do if the character is not a space.