The call:

rewind(stream)

is equivalent to:

(void) fseek(stream, 0L, SEEK_SET)

except that rewind() also clears the error indicator.

The rewind() function returns no value.

Refer to fseek(3C) with the exception of EINVAL which does not apply.

Because rewind() does not return a value, an application wishing to detect errors should clear errno, then call rewind(), and if errno is non-zero, assume an error has occurred.

See attributes(5) for descriptions of the following attributes:

fseek(3C), attributes(5)