Write a program to print all the binary strings of length n

#include<stdio.h>
main()
{
int n;
printf("enter n value\n");
scanf("%d",&n);
printall(n);
}
void printall(int n)
{
char out[30]="";
aux_printall(out,0,n);

}
void aux_printall(char out[], int d, int n)
{
if(d==n) // print output
{
out[n]='\0';
printf("%s\n",out);
return;
}

out[d]='0';
aux_printall(out,d+1,n);
out[d]='1';
aux_printall(out,d+1,n);
}