stream_set_write_buffer()

(PHP 4 >= 4.3.0, PHP 5, PHP 7)

Sets write file buffering on the given stream

说明

stream_set_write_buffer(resource $stream,int $buffer): int

Sets the buffering for write operations on the given$streamto$bufferbytes.

参数

$stream: The file pointer.
$buffer: The number of bytes to buffer.If$bufferis 0 then write operations are unbuffered. This ensures that all writes withfwrite()are completed before other processes are allowed to write to that output stream.

返回值

Returns 0 on success, or another value if the request cannot be honored.

范例

Example #1stream_set_write_buffer()example

The following example demonstrates how to usestream_set_write_buffer()to create an unbuffered stream.

<?php
$fp = fopen($file, "w");
if ($fp) {
  if (stream_set_write_buffer($fp, 0) !== 0) {
      // changing the buffering failed
  }
  fwrite($fp, $output);
  fclose($fp);
}
?>

参见

fopen() 打开文件或者 URL
fwrite() 写入文件（可安全用于二进制文件）

Trying to use stream_set_write_buffer on a local file will always fail according to this note from 2003.
http://grokbase.com/t/php/php-internals/0351gp6xtn/stream-set-write-buffer-does-not-work
Example:
$fp = fopen("localfile.txt", "w");
if (stream_set_write_buffer($fp, 0) !== 0) {
  // changing the buffering failed is always true on local files
}