Thread: help with code

Please help! I have this, can it be shortened at all? Plus, when it prints out, it prints out the entered data in reverse order, such as 4567 is entered, and 7654 is printed after the bits are printed. Any thoughts to flip this around to show in the correct order? Thanks in advance!


#include <limits.h>
#include <stdio.h>

int pack(int, int, int, int);
int unpack(int, int);
void bit_print(int);

int main()
{
int i, j, k, l, m, un, pa;
system("cls");

printf("Please enter 4 numbers: ");
printf("\nDo not space between\n");
scanf("%1d%1d%1d%1d", &i, &j,&k, &l);
pa = pack(i,j,k,l);
printf("The numbers you entered are: ");
printf("%3d%3d%3d%3d\n", i,j,k,l);
bit_print(pa);
printf("\n");
for(m = 0; m < 4; ++m)
{
un=unpack(pa, m);
printf("%d\n", un);
}
return 0;
}

void bit_print(int e)
{
int r;
int w = sizeof(int) * CHAR_BIT;
int mask = 1 << (w-1);

for (r=1; r<=w; ++r)
{
putchar(((e&mask)==0) ? '0':'1');
e <<=1;
if (r % 4==0 && r < w)
putchar(' ');
}
}

int pack(int a, int b, int c, int d)
{

int p = a;

p = (p<<4)|a;
p = (p<<4)|b;
p = (p<<4)|c;
p = (p<<4)|d;

return p;
}

int unpack(int x, int z)
{
int y = z * 4;
unsigned mask = 15;

mask <<= y;
return ((x & mask) >> y );
}