the following function gets an integer value and converts it to a string ("strint") without using any library functions: Although it is long but it works.

void GetInt(char *strint, int val)
{
char *str;
int length=0;
int rev = 0,i=0,num;

/* get the length of int number */
num=val;
do{
i++;
num=num/10;
}
while(num==0);

/* allocate memory */
str=new char[i];
strint=new char[i];

/* convert it to character , */
while (val > 0)
{
int a = val % 10;
str[length++] = a | '0';
val /= 10;
}
str[length]='\0';
length--;
while (length >= 0)
{
strint[rev++] = str[length--];
}

strint[rev] = '\0';

}
void io_display(const char *str, int row, int col, int len){
io_move(row, col);
if(len <= 0){
io_putstr(str);
}
else{
int i;
for(i=0;i<len;i++)
{
str[i]? io_putch(str[i]) :io_putch(' ');
}

}
}