std::rewind

 

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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

fseek

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