In the C language, the rewind function is used to set the position of a stream to the very beginning. I'd like to ask if there's an equivalent function that moves the stream position to the left by one token only.

For example, I have a file called FooFile.txt that contains several lines of sequences of integers separated by a " " whitespace character.

```
int main()
{
    // open file stream.
    FILE *FooFile = fopen("FooFile.txt" , "r");
    int Bar = 0;

    // loop through every integer token in the file stream.
    while ( fscanf( FooFile, "%d", &Bar ) == 0 )
    {
        // I don't want to reset the stream to the very beginning.
        // rewind( FooFile );
        // I only need to move the stream back one token.

        Bar = fscanf ( FooFile, "%d", &Bar )
        Bar = fscanf ( FooFile, "%d", &Bar )
    }
}

```