how does random work in C code example

Example 1: c generate random number

#import 
#import 

int r;
srand(time(NULL));
r = rand();

/* 
This will give you a pseudo random integer between 0 and RAND_MAX. 
srand(time(NULL)) is used to give it a random starting seed, based on the
current time. rand() could be used without it, but would always return the
same sequence of numbers.
To generate a random number in between 0 (included) and X (excluded), do
the following:
*/

#import 
#import 

int r;
srand(time(NULL));
r = rand() % X;

Example 2: random number generator c

rand() % (maxlimit + 1 - minlimit) + minlimit;