terminal emulator... in a terminal?

termios.h

#include <iostream>
#include <unistd.h>
#include <termios.h>
#include <cstdio>
#include <vector>
#include <string>

using namespace std;


char getch() {
	char buf = 0;
	struct termios old = {0};
	if (tcgetattr(0, &old) < 0)
		perror("tcsetattr()");
	old.c_lflag &= ~ICANON;
	old.c_lflag &= ~ECHO;
	old.c_cc[VMIN] = 1;
	old.c_cc[VTIME] = 0;
	if (tcsetattr(0, TCSANOW, &old) < 0)
		perror("tcsetattr ICANON");
	if (read(0, &buf, 1) < 0)
		perror ("read()");
	old.c_lflag |= ICANON;
	old.c_lflag |= ECHO;
	if (tcsetattr(0, TCSADRAIN, &old) < 0)
		perror ("tcsetattr ~ICANON");
	return (buf);
}

void run( string cmd )
{
	cout << endl;
	//cout << "cmd: " << cmd << endl;
}

void clear( vector<string>::iterator it )
{
	cout << "\r";
	for (int i = 0; i < (*it).size() + 2; ++i)
		cout << " ";
	cout << "\r";
}

void backspace( vector<string>::iterator it )
{
	if( (*it).size() == 0 ) return;
	(*it).resize( (*it).size() - 1 );
}

int main(int argc, char const *argv[])
{
	cout << "..." << endl;
	char  c = 0
		, l;
	vector<string> history;
	history.push_back( string("") );
	static vector<string>::iterator it = history.begin();	
	do
	{
		l = c;
		c = getch();
		switch( c )
		{
			case '\n':
				cout << endl;
				run( *it );
				history.push_back( *it );
				history.back();
				it = history.begin();
				history.front() = "";
			break;

			case 'q':
				if( l == 'q' ) continue;
				cout << "\rType 'q' again to quit.                   " << endl;
				cout << *it << flush;
			break;

			case 0x7f:
				backspace( it );
			break;

			default:
				if( l == '[' && c == 'A' )
				{
					backspace( it );
					if( it != history.end() -1 )
						it++;
				}
				else if( l == '[' && c == 'B' )
				{
					backspace( it );
					if( it != history.begin() )
						it--;	
				}
				else if( isprint(c) )
				{
					(*it).append<char>(1,c);
				}
				
		}
		clear( it );
		cout << "\r" << *it << flush;
	} while( c != 'q' || l != 'q' );


	cout << endl;
	return 0;
}