Simple formatting question..

New here, thought I'd start off with something easy.

Ok I have this function that converts an (int) into a 4 octect IP address, storing each octet of the IP into an array. To output this as a normal IP address, I have to add the dots between each number. The code goes as thus ( all you really need to note is the cout statement at the bottom )-

Code:

    int i = 0;
    int n = 24;
    IP octet[4];  //unsigned int

    for ( i = 0 ; i < 4 ; i++)
    {
        octet[i] = ( ( address >> n ) & 255 );
        n -=8;
    }

cout << octet[0] << "." << octet[1] << "." << octet[2] << "." << octet[3];

So the output looks something like 192.24.159.1, just as an example.

My question is, I am going to output this in a list with multiple lines, and will be outputting items after this on the same line. So I need to set width to 16 and align this IP to the left, then output the rest of the line uniformly. However, I am unsure how to do this, since the setw() function only grabs the next item on the output stream ( in this case, octet[0] ), and the rest will be pushed a dozen or so spaces over. I need to find a way to make it so this entire bit of code ( the cout statement of this function, basically ) is aligned to the left of a 16-space spot. Not sure if this would involve changing my output, but I'm up for any suggestions.

Sorry if this description is not adequate, I can sure repost if necessary. Thanks for any help.

is using tabs after your last octet acceptable? depending on your environment, one tab may be enough to do what you want...

in other words, have you tried

Code:

cout << octet[0] << "." << octet[1] << "." << octet[2] << "." << octet[3]<<'\t';

if not, what about blank spaces? by that I mean can you output this:

Code:

192.168.  0. 12

if so, try using width()

Actually the tab will work perfectly. Thanks! I knew it had to be something simple that just wasn't coming to mind.

Seems like a perfect opportunity to use a class. I don't know your specific implementation but you could probably adapt it or come up with something similar (could probably be improved upon as well ie..another constructor to accept an array of 4 ints, I whipped it up real quick).

OctetAddress.h

Code:

#ifndef OCTETADDRESS_H
#define OCTETADDRESS_H

#include <iostream>
#include <string>
#include <sstream>

using std::cout;
using std::ostringstream;
using std::string;

class OctetAddress {
	
	private:
		string octetString;
		int octetField[4];
		void setOctetString();
	
	public:
		OctetAddress( int = 0, int = 0, int = 0, int = 0 );
		void setOctet( int = 0, int = 0, int = 0, int = 0 );
		string getOctetString() const;

};

OctetAddress::OctetAddress( int a, int b, int c, int d )
{
	setOctet( a, b, c, d );
}

void OctetAddress::setOctet( int a, int b, int c, int d )
{
	octetField[0] = ( a > 255 || a < 0 ? 0 : a );	//
	octetField[1] = ( b > 255 || b < 0 ? 0 : b );	// Ensure values
	octetField[2] = ( c > 255 || c < 0 ? 0 : c );	// are in range
	octetField[3] = ( d > 255 || d < 0 ? 0 : d );	//
	setOctetString();
}

void OctetAddress::setOctetString()
{
	ostringstream buildString;
	buildString << octetField[0] << "." << octetField[1] << "." << octetField[2] << "." << octetField[3];
	octetString = buildString.str();
}

string OctetAddress::getOctetString() const
{
	return octetString;
}

#endif

And a simple example how it's easy to provide organized output.

sampleUse.cpp

Code:

#include <iostream>
#include <iomanip>
#include "OctetAddress.h"

using std::cout;
using std::cin;
using std::setw;
using std::left;
using std::endl;

int main()
{
	
	int octet[4];
	
	cout << "Enter 4 ints:" << endl;
	for (int n = 0 ; n < 4 ; n++ )
		cin >> octet[n];
	
	OctetAddress ipAddress1( octet[0], octet[1], octet[2], octet[3] );
	OctetAddress ipAddress2;
	
	
	cout << setw(16) << left << ipAddress1.getOctetString() << "random text" << endl;
	cout << setw(16) << left << ipAddress2.getOctetString() << "random text" << endl;
	
	ipAddress2.setOctet( 192, 168, 0, 1 );
	cout << setw(16) << left << ipAddress2.getOctetString() << "random text" << endl;
	
	return 0;
}

If you want more control over the output than a tab, you could also do it like this:

Code:

int octet[] = {192, 24, 159, 1};

//Create a variable that allows you use the << operator to append non-string types:
stringstream combined_string; 
combined_string << octet[0] << "." << octet[1] << "." << octet[2] << "." << octet[3];

//Use the str() function to get the contents of the variable:
cout << combined_string.str()<< "xxxx" <<endl;  

//Use setw() and left to format the output for the variable, then return to default settings:
cout<<setw(16)<<left<<combined_string.str()<<setw(0)<<right<<"xxxx"<<" yyyy"<<endl;

You need to include <sstream> and <iomanip>.

Thanks a bunch guys, I'll give some of that a shot. I really appreciate the help