General - Help me i dont know how to reduce the code

This is an program to convert an ip address to binairy, but the code is a bit large for that every thing is times 4, i tryed arrays but wouldn't work for me.

can some one help me.

#include <iostream>
#include <string>

using namespace std;

int main(void)
{
//Declerations for the strings and integers.
//Because ip address work on 8 bit system.
int bit[8] = {128, 64, 32, 16, 8, 4, 2, 1};
//The numbers used for increasing its binairy
int binairy[8] = {10000000, 1000000, 100000, 10000, 1000, 100, 10, 1};
//Containers for the decimal and binairy conversion
int ipsec1, ipsec2, ipsec3, ipsec4;
int binsec1, binsec2, binsec3, binsec4;
//a stop so you can see the result
int test;
//4 strings so the binairy can be shown correct as 8 bit
string bintext1, bintext2, bintext3, bintext4;
//a few assignings because it wouldn't work without it :S
binsec1 = 0;
binsec2 = 0;
binsec3 = 0;
binsec4 = 0;

cout << "This is an ip to binairy converter.\n";
cout << "Please input the ip in 4 sections.\n";
//Here comes the input for the ip address in 4 chunks
start:
cout << "Please input section: ";
cin >> ipsec1;
cout << "Please input section: ";
cin >> ipsec2;
cout << "Please input section: ";
cin >> ipsec3;
cout << "Please input section: ";
cin >> ipsec4;
//This is the routine for the whole thing and some error checking
sec1:
if (ipsec1 == 0)
{
binsec1 = 0;
goto sec2;
}

if (ipsec1 > 255 || ipsec1 < 1)
{
system("cls");
cout << "Invalid input, please try again.\n";
goto sec1;
}
//This is the math system for converting it
for (int t=0; t < 8; t++)
{
if (ipsec1 >= bit[t])
{
ipsec1 = ipsec1 - bit[t];
binsec1 = binsec1 + binairy[t];
}
}
//the same but just for the 2de chunk
sec2:
if (ipsec2 == 0)
{
binsec2 = 0;
goto sec3;
}

if (ipsec2 > 255 || ipsec2 < 1)
{
system("cls");
cout << "Invalid input, please try again.\n";
goto sec2;
}

for (int t=0; t < 8; t++)
{
if (ipsec2 >= bit[t])
{
ipsec2 = ipsec2 - bit[t];
binsec2 = binsec2 + binairy[t];
}
}
//the same but for the 3de chunk
sec3:
if (ipsec3 == 0)
{
binsec3 = 0;
goto sec4;
}

if (ipsec3 > 255 || ipsec3 < 1)
{
system("cls");
cout << "Invalid input, please try again.\n";
goto sec3;
}

for (int t=0; t < 8; t++)
{
if (ipsec3 >= bit[t])
{
ipsec3 = ipsec3 - bit[t];
binsec3 = binsec3 + binairy[t];
}
}
//the same but for the 4th chunk
sec4:
if (ipsec4 == 0)
{
binsec4 = 0;
goto end;
}
if (ipsec4 > 255 || ipsec4 < 1)
{
system("cls");
cout << "Invalid input, please try again.\n";
goto sec4;
}

for (int t=0; t < 8; t++)
{
if (ipsec4 >= bit[t])
{
ipsec4 = ipsec4 - bit[t];
binsec4 = binsec4 + binairy[t];
}
}

end:
// check and add of 0's if needed so it would be shown correct for instead 10 it is shown as 00000010
if (binsec1 >= 1000000 && binsec1 <= 1111111) bintext1 = "0";
if (binsec1 >= 100000 && binsec1 <= 111111) bintext1 = "00";
if (binsec1 >= 10000 && binsec1 <= 11111) bintext1 = "000";
if (binsec1 >= 1000 && binsec1 <= 1111) bintext1 = "0000";
if (binsec1 >= 100 && binsec1 <= 111) bintext1 = "00000";
if (binsec1 >= 10 && binsec1 <= 11) bintext1 = "000000";
if (binsec1 == 1) bintext1 = "0000000";
if (binsec1 == 0) bintext1 = "00000000";
//the same but for the next chunk
if (binsec2 >= 1000000 && binsec2 <= 1111111) bintext2 = "0";
if (binsec2 >= 100000 && binsec2 <= 111111) bintext2 = "00";
if (binsec2 >= 10000 && binsec2 <= 11111) bintext2 = "000";
if (binsec2 >= 1000 && binsec2 <= 1111) bintext2 = "0000";
if (binsec2 >= 100 && binsec2 <= 111) bintext2 = "00000";
if (binsec2 >= 10 && binsec2 <= 11) bintext2 = "000000";
if (binsec2 == 1) bintext2 = "0000000";
if (binsec2 == 0) bintext2 = "00000000";
//the same but for the next chunk
if (binsec3 >= 1000000 && binsec3 <= 1111111) bintext3 = "0";
if (binsec3 >= 100000 && binsec3 <= 111111) bintext3 = "00";
if (binsec3 >= 10000 && binsec3 <= 11111) bintext3 = "000";
if (binsec3 >= 1000 && binsec3 <= 1111) bintext3 = "0000";
if (binsec3 >= 100 && binsec3 <= 111) bintext3 = "00000";
if (binsec3 >= 10 && binsec3 <= 11) bintext3 = "000000";
if (binsec3 == 1) bintext3 = "0000000";
if (binsec3 == 0) bintext3 = "00000000";
//the same but for the next chunk
if (binsec4 >= 1000000 && binsec4 <= 1111111) bintext4 = "0";
if (binsec4 >= 100000 && binsec4 <= 111111) bintext4 = "00";
if (binsec4 >= 10000 && binsec4 <= 11111) bintext4 = "000";
if (binsec4 >= 1000 && binsec4 <= 1111) bintext4 = "0000";
if (binsec4 >= 100 && binsec4 <= 111) bintext4 = "00000";
if (binsec4 >= 10 && binsec4 <= 11) bintext4 = "000000";
if (binsec4 == 1) bintext4 = "0000000";
if (binsec4 == 0) bintext4 = "00000000";
// the real printing as an whole
cout << bintext1 << binsec1 << "." << bintext2 << binsec2 << "." << bintext3 << binsec3 << "." << bintext4 << binsec4 << "\n";
//and an pause so you could see the result
cin >> test;
return 0;
//end
}

cin.fail() will be true if the user entered 14.a.51.61 - i.e. expecting a number but getting a letter.

The ignore call could be replaced to verify that it is indeed the . it's supposed to be.

The code is untested - it might not work, but it should at least be close.

Thanks for the short version of it, but can some one explain the code to me, and to be precise the part of ostringstream, and what it does and to use it, sorry i know but i'm still learning :P.

thx, for the reply