Thread: pass two string in this program...

i am trying to write a program that work like sprintf but i have one problem!
when I pass two string into string_print function output isnt correct why?!
for example
string a="x %s %s %d";
string_print(a,"dsad","ds",5);
and how can i fix this warning "second parameter of 'va_start' not last named argument"

Code:

#include <iostream>
#include<windows.h>
#include <stdarg.h>
#include <stdio.h>
#include<string>
using namespace std;
string string_print(string a,...);


string string_print(string a,...)
{
  string result;
  int i=0,arg_num=0,T_str=0;
  int size;


   /******calculate arg numbers */
  while(a[i++]!='\0')
    if(a[i]=='%')
      arg_num++;
  va_list listptr;
  va_start(listptr,arg_num);
  /******start puting into string*/
  for(i=0;i<arg_num;i++)
    while(a[T_str++]!='\0')
      if(a[T_str]=='%')
      {
        if(a[T_str+1]=='d')    /******  %d */
          {
             a[T_str]= va_arg(listptr,int)+'0';
             size=a.size();
             a.append(" ");
             for(i=T_str+1;i<size;i++) //move one character left  (example: ob %5 f-->ob 5 f)
             a[i]=a[i+1];
          }


         if(a[T_str+1]=='c')
           {
             a[T_str]= va_arg(listptr,int);
             size=a.size();
             a.append(" ");
             for(i=T_str+1;i<size;i++) //move array one character left
             a[i]=a[i+1];
           }
         if(a[T_str+1]=='s')
           {


               int f_e=0;
               int size_a,size_input,c_size_input;
               string input;
               /***put input string at the end of a and get the input size*/
              input=va_arg(listptr,char*);
              size_input=strlen(input.c_str());
              a.append(input.c_str());
              /************************************/
              size_a=strlen(a.c_str());//get new size
              c_size_input=size_input;//c:copy


/***************put s equal to input size (example %s,dfg-->%sss)*******/
             while(c_size_input>1)
               {
                  a.append(" "); //add 1   to string size
                  c_size_input--;
                  for(i=size_a+f_e;i>T_str+1;i--)
                     a[i]=a[i-1];
                  f_e++;
               }
/***************put input item instead of s*******/
          size_a=strlen(a.c_str());
          c_size_input=size_input;
          int first_ch=size_a-size_input; //value of first input character
          for(int first_put=T_str+1;c_size_input>0;c_size_input--)
             a[first_put++]=a[first_ch++];




/***************make extra items in a NULL*******/
            c_size_input=size_input;
            for(int first_null=size_a-size_input;c_size_input>-2;c_size_input--)
              a[first_null++]='\0';
/***************move  one character left (example %fd d-->fd d)**********/
           for(i=T_str;i<size_a;i++)
             a[i]=a[i+1];


           }//end of if
      }//end of while
  va_end(listptr );
  return a;
}
int main()
{
  string a="x %s %c  %d";
  cout<<string_print(a,"dsad",'g',5);




    return 0;
}//12 1