Bitmanipulation

#include <stdio.h>
#include <conio.h>

#define nl printf("\n")

void showBit (unsigned int);
void setBit (unsigned int *, int);
void clearBit (unsigned int *, int);
int isSet (unsigned int a, int pos);
int showBit2 (unsigned int a);
void invertBit (unsigned int *a, int pos);
int numberofsetBit (unsigned int a);
int main (void)
{
    unsigned int i=3;
    unsigned int pos=5;
    int set=0;



    showBit2 (i);
    nl;
    setBit (&i,pos);
    showBit (i);
    nl;
    printf ("%X",i);
    clearBit (&i, pos);
    nl;
    showBit (i);
    if (isSet (i,pos))
        clearBit (&i,pos);
    nl;
    showBit (i);
    invertBit (&i, 10);
    nl;
    showBit (i);
    nl;
    set=numberofsetBit (i);
    printf ("%d",set);

    getch ();
    return 0;
}



void showBit (unsigned int a)
{

    unsigned int mask=1;
    int i=0;

    mask<<=sizeof(int)*8-1; //1 ganz nach links

    for (i=0; i<sizeof(int)*8; i++)
    {
                // if ((a&mask)==mask)
            if (a&mask)

            printf ("%c",'1');
        else
            printf ("%c",'0');

        mask >>=1; //eine Stelle nach rechts
    }
}

void setBit (unsigned int *a, int pos)

{

    unsigned int mask=1;

    if (pos>=0 && pos<sizeof(int)*8)
    {
        mask=mask<<pos;
        *a=*a|mask;
    }



}

void clearBit (unsigned int *a, int pos)
{

    unsigned int mask=1;

    if (pos>=0 && pos<sizeof(int)*8)
    {
        mask=mask<<pos; //1 auf die Position "pos" bringen
        mask=~mask;
        *a=*a&mask;
    }


}

int isSet (unsigned int a, int pos)
{
    int control=0;
    unsigned int mask=1;

    if (pos>=0 && pos<sizeof(int)*8)
    {
        mask=mask<<pos; //1 auf die Position "pos" bringen
        control=a&mask;
    }


    return control;
}


int showBit2 (unsigned int a)
{
    int i=sizeof(a)*8-1;

    for (;i>=0; i--)
    {
        if (isSet(a,i))
            printf ("%c",'1');
        else
            printf ("%c",'0');
    }


}

void invertBit (unsigned int *a, int pos)
{
    unsigned int mask=1;

    if (pos>=0 && pos<sizeof(int)*8)
    {
        mask=mask<<pos;
        *a=*a^mask;


    }



}

int numberofsetBit (unsigned int a)
{
    unsigned int mask=1;
    int z=0;
    int pos=0;

    do
    {
        if(isSet (a,pos))
            z++;

        pos++;

    }while (pos<sizeof(int)*8);
        return z;
}