rewind
The latest version of this topic can be found at rewind.
Repositions the file pointer to the beginning of a file.
Syntax
void rewind(
FILE *stream
);
Parameters
stream
Pointer to FILE structure.
Remarks
The rewind function repositions the file pointer associated with stream to the beginning of the file. A call to rewind is similar to
(void) fseek( stream, 0L, SEEK_SET );
However, unlike fseek, rewind clears the error indicators for the stream as well as the end-of-file indicator. Also, unlike fseek, rewind does not return a value to indicate whether the pointer was successfully moved.
To clear the keyboard buffer, use rewind with the stream stdin, which is associated with the keyboard by default.
If stream is a NULL pointer, the invalid parameter handler is invoked, as described in Parameter Validation. If execution is allowed to continue, this function returns and errno is set to EINVAL.
For information on these and other error codes, see _doserrno, errno, _sys_errlist, and _sys_nerr.
Requirements
| Routine | Required header |
|---|---|
| rewind | <stdio.h> |
For additional compatibility information, see Compatibility in the Introduction.
Libraries
All versions of the C run-time libraries.
Example
// crt_rewind.c
/* This program first opens a file named
* crt_rewind.out for input and output and writes two
* integers to the file. Next, it uses rewind to
* reposition the file pointer to the beginning of
* the file and reads the data back in.
*/
#include <stdio.h>
int main( void )
{
FILE *stream;
int data1, data2;
data1 = 1;
data2 = -37;
fopen_s( &stream, "crt_rewind.out", "w+" );
if( stream != NULL )
{
fprintf( stream, "%d %d", data1, data2 );
printf( "The values written are: %d and %d\n", data1, data2 );
rewind( stream );
fscanf_s( stream, "%d %d", &data1, &data2 );
printf( "The values read are: %d and %d\n", data1, data2 );
fclose( stream );
}
}
Output
The values written are: 1 and -37
The values read are: 1 and -37
.NET Framework Equivalent
Not applicable. To call the standard C function, use PInvoke. For more information, see Platform Invoke Examples.