std::basic_istream<CharT,Traits>::seekg

basic_istream& seekg( pos_type pos );

basic_istream& seekg( off_type off, std::ios_base::seekdir dir );

Sets input position indicator of the current associated streambuf object.

seekg behaves as UnformattedInputFunction, except that gcount() is not affected. After constructing and checking the sentry object,

Parameters

Return value

*this.

Exceptions

If an internal operation throws an exception, it is caught and badbit is set. If exceptions() is set for badbit, the exception is rethrown.

Notes

seekg(n) is not necessarily equivalent to seekg(n, ios::beg). std::basic_ifstream, for example, requires the absolute position n to come from tellg().

Example

#include <iostream>
#include <string>
#include <sstream>
 
int main()
{
    std::string str = "Hello, world";
    std::istringstream in(str);
    std::string word1, word2;
 
    in >> word1;
    in.seekg(0); // rewind
    in >> word2;
 
    std::cout << "word1 = " << word1 << '\n'
              << "word2 = " << word2 << '\n';
}

word1 = Hello,
word2 = Hello,

Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

See also