basic_ostream::seekp

Randomly move to a position in an output stream.

  basic_ostream<charT, traits>& seekp(pos_type);

  basic_ostream<charT, traits>& seekp

        (off_type, iosbase::seekdir);  

The function seekp is overloaded to take a single argument of a pos_type pos that calls rdbuf()->pubseekpos(pos). It is also overloaded to take two arguments: an off_type off and i os_base::seekdir type dir that calls rdbuf()->pubseekoff(off, dir).

Returns the this pointer.

basic_istream::seekg , basic_ostream::tellp

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

std::string motto = "CodeWarrior - Software at Work"; 

int main()
{ 
using namespace std;
   ostringstream ostr(motto); 
   streampos cur_pos, start_pos;
   cout << "The original array was :\n" 
     << motto << "\n\n"; 
     // associate buffer

   stringbuf *strbuf(ostr.rdbuf()); 
    streamoff str_off = 10; 
   cur_pos = ostr.tellp();
   cout << "The current position is " 
          << cur_pos.offset()
          << " from the beginning\n";

   ostr.seekp(str_off); 
   cur_pos = ostr.tellp(); 
   cout << "The current position is " 
          << cur_pos.offset() 
          << " from the beginning\n";

   strbuf->sputc('\0');
   cout << "The stringbuf array is\n" 
      << strbuf->str() << "\n\n";
   cout << "The ostringstream array is still\n" 
      << motto;

    return 0;
}

Results:

  The original array was :

  CodeWarrior - Software at Work

  The current position is 0 from the beginning

  The current position is 10 from the beginning

  The stringbuf array is

  CodeWarrior

  The ostringstream array is still

  CodeWarrior - Software at Work