streamWrapper::stream_seek()
(PHP 4 >= 4.3.2, PHP 5, PHP 7)
Seeks to specific location in a stream
说明
public streamWrapper::stream_seek(int $offset,int $whence= SEEK_SET): bool
This method is called in response tofseek().
The read/write position of the stream should be updated according to the$offsetand$whence.
参数
- $offset
The stream offset to seek to.
- $whence
Possible values:
SEEK_SET
- Set position equal to$offsetbytes.SEEK_CUR
- Set position to current location plus$offset.SEEK_END
- Set position to end-of-file plus$offset.
返回值
ReturnTRUE
if the position was updated,FALSE
otherwise.
注释
Note:If not implemented,
FALSE
is assumed as the return value.
Note:Upon success,streamWrapper::stream_tell()is called directly after callingstreamWrapper::stream_seek().IfstreamWrapper::stream_tell()fails, the return value to the caller function will be set to
FALSE
Note:Not all seeks operations on the stream will result in this function being called. PHP streams have read buffering enabled by default (see alsostream_set_read_buffer()) and seeking may be done by merely moving the buffer pointer.
参见
fseek()
在文件指针中定位
Please notice that the return value of this function is a boolean but the return value of fseek is 0 for ok and -1 for failure. Please use this implementation when working with files: function stream_seek($offset, $whence) { if(0 === fseek($this->_handler, $offset, $whence)){ return true; } return false; }