help with comparing data from a file

[loso44x]

data is being read from a txt file with this format

Meet the Fockers,12345678918,04/19/2005,116
Meet the Parents,PG,03/06/2001,108
Fantastic Four,PG-13,07/10/2005,99
Harry Potter: Prisoner of Azkaban,Not-Rated,11/23/2004,142
Hitch,PG-13,07/02/2005,103

lets say if length is > than 3 digits or a negative number is in the input file then it would print invalid.. how would i go about doing that.. i tried changing char length[50] to int length and changed to %d in fscanf but then the displayed weird numbers when i printed it for testing...

typedef struct {
char title[50];
char rating[50];
char date[50]; 
char length[50];
} Videos;

---------------

          fscanf(in_file, "\n%50[^,],%50[^,],%50[^,],%s",movies[i].title, movies[i].rating,movies[i].date,&movies[i].length);

[itsme86]

Read the last number in as a string and just do if(input[0] == '-' || strlen(input) > 3) to test for invalidity.

[loso44x]

what does input[0] == '-' do? how does that check for all the characters?

[itsme86]

It checks if the first character is a '-' (i.e. if the number is negative.)