(no version information, might be only in CVS)
php_stream_seek -- ストリーム内で移動する
( php_stream * stream, off_t offset, int whence)
php_stream_seek() repositions the internal
position of stream.
The new position is determined by adding the offset
to the position indicated by whence.
If whence is set to SEEK_SET,
SEEK_CUR or SEEK_END the offset
is relative to the start of the stream, the current position or the end of the stream, respectively.
php_stream_seek() returns 0 on success, but -1 if there was an error.
Not all streams support seeking, although the streams API will emulate a seek if
whence is set to SEEK_CUR
and offset is positive, by calling php_stream_read()
to read (and discard) offset bytes.
The emulation is only applied when the underlying stream implementation does not
support seeking. If the stream is (for example) a file based stream that is wrapping
a non-seekable pipe, the streams api will not apply emulation because the file based
stream implements a seek operation; the seek will fail and an error result will be
returned to the caller.