Thread: fgets prompt in while loop "skips"

Originally Posted by Jesdisciple

Alright, I reverted the other bugfix to test this one, but the output is the same as it was at the beginning... Is my condition giving a bad "false" result?

Code:

	fgets(input, (int)length, stdin);
	if(strlen(input) == length && input[length - 1] != '\n'){
		while ((ch = getchar()) != '\n' && ch != EOF)
			/* Clean out the buffer. */;
	}

EDIT: Never mind; I needed to subtract 1 from length both times. Thanks again!

There is no reason to check if strlen(input) == length - justcheck if input[strlen(input)-1] != '\n' - it's not really important to only do this when you have strlen(input) == length-1, since the expensive part of the check is to do strlen - so we may just as well simply compare the end of the string with newline. It makes it ONE check, rather than two, making the code simpler.

I personally would probably just set a max line length of some rather large number, say 256 [assuming you do not have some really long input expected, in which case a larger number is appropriate]. If you do that, you can probably ignore checking for newline in the input string [although you probably will, one way or another deal with the fact that there is a newline at the end of the string - however, that is a slightly different matter].

--
Mats

The reason I didn't do that is that the string may be shorter than the char *. For example, say I had a third option "maybe." Then I need to ask fgets for 7 characters, and the response might be "no":
[n][o][\n][\0][?][?][?]
And then the next-to-last character is probably not a newline, and the user is confused that the program is hanging on an empty line...

EDIT: DUH! I'm sorry, you're right and I'm contradicting myself...

EDIT2: ... And I forgot to reply to the rest of your message... I know modern computers aren't hurting for RAM, but I prefer to only ask for what I'll use.