Php/docs/streamwrapper.stream-seek

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streamWrapper::stream_seek

(PHP 4 >= 4.3.2, PHP 5, PHP 7)

streamWrapper::stream_seekSeeks 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 to fseek().

The read/write position of the stream should be updated according to the offset and whence.


参数

offset

The stream offset to seek to.

whence

Possible values:

  • SEEK_SET - Set position equal to offset bytes.
  • SEEK_CUR - Set position to current location plus offset.
  • SEEK_END - Set position to end-of-file plus offset.

Note:

The current implementation never sets whence to SEEK_CUR; instead such seeks are internally converted to SEEK_SET seeks.


返回值

Return true 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 calling streamWrapper::stream_seek(). If streamWrapper::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 also stream_set_read_buffer()) and seeking may be done by merely moving the buffer pointer.

参见