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# rewind

Input-Output Functions

Rewinds a file.

    void rewind( FILE *file_pointer);

file_pointer | A pointer to the file to rewind.

For rewind details, refer to your C language documentation.

## Return Values

This function has no return value.

## Example

This example creates a log file and writes the following to it:

- the string "Vuser"

- the integer "Vuser ID"

the time, as returned by the time function.

To read these values back again, the file cursor is moved to the beginning of the file, using rewind.

Copy code

    #include <time.h>
    #include <stdio.h>
            #ifdef unix
                char *filename = "/tmp/logfile.txt";
            #else
                char *filename = "c:\\logfile.txt";
            #endif
        FILE* file, thetime;
        int id, id2;
        time_t t;
        char s[32];
        // Create a new file
        if ((file = fopen(filename, "w+" )) == NULL) {
            lr_output_message ("Unable to create %s", filename);
            return -1;
        }
        // Write the Vuser ID and time
        lr_whoami (&id, NULL, NULL);
        fprintf(file, "Vuser %d %ld", id, time(&t));
        // Now read what we've just written. Rewind to start of file
        rewind(file);
        fscanf(file, "%s", &s);
        fscanf(file, "%d", &id2);
        fscanf(file, "%ld", &thetime);
        lr_output_message ("%s %d %ld", s, id2, thetime);
        fclose(file);

    Example: Output:
    Vuser -1 1020675497

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