std:: rewind

Moves the file position indicator to the beginning of the given file stream.

The function is equivalent to std:: fseek ( stream, 0 , SEEK_SET ) ; , except that end-of-file and error indicators are cleared.

The function drops any effects from previous calls to ungetc .

Parameters

Return value

(none)

Example

#include <array>
#include <cstdio>
 
int main()
{
    std::FILE* f = std::fopen("file.txt", "w");
    for (char ch = '0'; ch <= '9'; ch++)
        std::fputc(ch, f);
    std::fclose(f);
 
    std::array<char, 20> str;
    std::FILE* f2 = std::fopen("file.txt", "r");
 
    const unsigned size1 = std::fread(str.data(), 1, str.size(), f2);
    std::puts(str.data());
    std::printf("size1 = %u\n", size1);
 
    std::rewind(f2);
 
    const unsigned size2 = std::fread(str.data(), 1, str.size(), f2);
    std::puts(str.data());
    std::printf("size2 = %u", size2);
 
    std::fclose(f2);
}

0123456789
size1 = 10
0123456789
size2 = 10

See also