std::rewind (3) Linux Manual Page

std::rewind – std::rewind

Synopsis

Defined in header<cstdio>

    void rewind(std::FILE *stream);

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

stream – file stream to modify

Return value

(none)

Example

// Run this code

#include <cstdio>
int main()

{
    std::FILE *f;
    char ch;
    char str[20];
    f = std::fopen("file.txt", "w");
    for (ch = '0'; ch <= '9'; ch++) {
        std::fputc(ch, f);
    }
    std::fclose(f);

    std::FILE *f2 = std::fopen("file.txt", "r");
    unsigned int size = std::fread(str, 1, 10, f2);
    std::puts(str);
    std::printf("\n%u\n", size);
    std::rewind(f2);
    unsigned int size2 = std::fread(str, 1, 10, f2);
    std::puts(str);
    std::printf("\n%u", size2);
    std::fclose(f2);
}

See also

      moves the file position indicator to a specific location in a file
fseek (function)