Write a C program that will only list all subdirectories in alphabetical order from current directory.

#include <stdio.h>
#include <stdlib.h>
#include <dirent.h>
int
main(void)
{
struct dirent **namelist;
int n;
int i=0;
n = scandir(".", &namelist, 0, alphasort);
if (n < 0)
perror("scandir");
else {
while (i<n) {
printf("%s\n", namelist[i]->d_name);
free(namelist[i]);
i++;
}
free(namelist);
}
}