fgets / buffer issue

[rethab]

Hi there

I'm facing some issue which I can't identify.
I have a structure 'album'. I try to read two albums from standard input. The first one works perfectly fine, but on the second one, it appears like this:

(..after first album has been read:)
title:
>band:
>

somehow, I can't enter a title, since 'band:' is already there..

I use this function to read an album:

void read_alb(struct album *alb) {
  char buffer[MAX];
 
  printf("title:\n>");
  fgets(buffer, MAX, stdin);
  trim(buffer); /* removes newline */
  strcpy((*alb).title, buffer);
 
  printf("band:\n>");
  fgets(buffer, MAX, stdin);
  trim(buffer);
  strcpy((*alb).band, buffer);
 
  printf("year:\n>");
  scanf("%d", &(*alb).year);
}

This function is called twice. As already mentioned, it works the first, but not the second time.

I'd be grateful if somebody could give me some advice.

Regards,
rethab

[Banfa]

That is because on line 15 you scan a number. Since generally stdin works on lines, the input is not passed to your program until the user presses enter then the code on line 15 leaves data in the input buffer, possibly any characters that can not be converted to a integer (letters for example) plus definitely the newline at the end of the users input.

That newline (plus the possible characters) are then read by your next call to fgets and assigned as the next title. You can verify this by typing the year of the first album and the title of the second album on a single line when prompted for a year. The title will make its way into the album title of the second album.

The problem is you have mixed line mode (fgets) reads and formatted reads (scanf). You could fix it simply by used fgets to read the user input for year and atoi, strtol or sscanf to convert the input string to an integer.

[rethab]

Thank you for your detailed response, Banfa. I'll fix that.

Regards,
rethab