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好用的phpheader下载函数

时间：2021-07-01 10:21:17 帮助过：69人阅读

  3. /**

  4. * 发送文件
  5. *
  6. * @param string $fileName 文件名称或路径
  7. * @param string $fancyName 自定义的文件名,为空则使用filename
  8. * @param boolean $forceDownload 是否强制下载
  9. * @param integer $speedLimit 速度限制,单位为字节,0为不限制,不支持windows服务器
  10. * @param string $$contentType 文件类型,默认为application/octet-stream
  11. *
  12. * @return boolean
  13. */
  14. function sendFile($fileName, $fancyName = '', $forceDownload = true, $speedLimit = 0, $contentType = '')
  15. {
  16. if (!is_readable($fileName))
  17. {
  18. header("HTTP/1.1 404 Not Found");
  19. return false;
  20. }
  21. $fileStat = stat($fileName);
  22. $lastModified = $fileStat['mtime'];

  23. $md5 = md5($fileStat['mtime'] .'='. $fileStat['ino'] .'='. $fileStat['size']);

  24. $etag = '"' . $md5 . '-' . crc32($md5) . '"';
  25. header('Last-Modified: ' . gmdate("D, d M Y H:i:s", $lastModified) . ' GMT');
  26. header("ETag: $etag");

  27. if (isset($_SERVER['HTTP_IF_MODIFIED_SINCE']) && strtotime($_SERVER['HTTP_IF_MODIFIED_SINCE']) >= $lastModified)

  28. {
  29. header("HTTP/1.1 304 Not Modified");
  30. return true;
  31. }
  32. if (isset($_SERVER['HTTP_IF_UNMODIFIED_SINCE']) && strtotime($_SERVER['HTTP_IF_UNMODIFIED_SINCE']) < $lastModified)
  33. {
  34. header("HTTP/1.1 304 Not Modified");
  35. return true;
  36. }
  37. if (isset($_SERVER['HTTP_IF_NONE_MATCH']) && $_SERVER['HTTP_IF_NONE_MATCH'] == $etag)
  38. {
  39. header("HTTP/1.1 304 Not Modified");
  40. return true;
  41. }
  42. if ($fancyName == '')
  43. {
  44. $fancyName = basename($fileName);
  45. }

  46. if ($contentType == '')

  47. {
  48. $contentType = 'application/octet-stream';
  49. }
  50. $fileSize = $fileStat['size'];

  51. $contentLength = $fileSize;

  52. $isPartial = false;
  53. if (isset($_SERVER['HTTP_RANGE']))
  54. {
  55. if (preg_match('/^bytes=(d*)-(d*)$/', $_SERVER['HTTP_RANGE'], $matches))
  56. {
  57. $startPos = $matches[1];
  58. $endPos = $matches[2];
  59. if ($startPos == '' && $endPos == '')
  60. {
  61. return false;
  62. }

  63. if ($startPos == '')

  64. {
  65. $startPos = $fileSize - $endPos;
  66. $endPos = $fileSize - 1;
  67. }
  68. else if ($endPos == '')
  69. {
  70. $endPos = $fileSize - 1;
  71. }
  72. $startPos = $startPos < 0 ? 0 : $startPos;
  73. $endPos = $endPos > $fileSize - 1 ? $fileSize - 1 : $endPos;
  74. $length = $endPos - $startPos + 1;
  75. if ($length < 0)
  76. {
  77. return false;
  78. }
  79. $contentLength = $length;
  80. $isPartial = true;
  81. }
  82. }

  83. // send headers

  84. if ($isPartial)
  85. {
  86. header('HTTP/1.1 206 Partial Content');
  87. header("Content-Range: bytes $startPos-$endPos/$fileSize");

  88. }

  89. else
  90. {
  91. header("HTTP/1.1 200 OK");
  92. $startPos = 0;
  93. $endPos = $contentLength - 1;
  94. }
  95. header('Pragma: cache');
  96. header('Cache-Control: public, must-revalidate, max-age=0');
  97. header('Accept-Ranges: bytes');
  98. header('Content-type: ' . $contentType);
  99. header('Content-Length: ' . $contentLength);

  100. if ($forceDownload)

  101. {
  102. header('Content-Disposition: attachment; filename="' . rawurlencode($fancyName). '"');//汉字自动转为URL编码
  103. header('Content-Disposition: attachment; filename="' . $fancyName. '"');
  104. }
  105. header("Content-Transfer-Encoding: binary");
  106. // header函数实现文件下载

  107. $bufferSize = 2048;

  108. if ($speedLimit != 0)
  109. {
  110. $packetTime = floor($bufferSize * 1000000 / $speedLimit);
  111. }
  112. $bytesSent = 0;
  113. $fp = fopen($fileName, "rb");
  114. fseek($fp, $startPos);
  115. //fpassthru($fp);

  116. while ($bytesSent < $contentLength && !feof($fp) && connection_status() == 0 )

  117. {
  118. if ($speedLimit != 0)
  119. {
  120. list($usec, $sec) = explode(" ", microtime());
  121. $outputTimeStart = ((float)$usec + (float)$sec);
  122. } // bbs.it-home.org
  123. $readBufferSize = $contentLength - $bytesSent < $bufferSize ? $contentLength - $bytesSent : $bufferSize;
  124. $buffer = fread($fp, $readBufferSize);
  125. echo $buffer;
  126. ob_flush();
  127. flush();
  128. $bytesSent += $readBufferSize;

  129. if ($speedLimit != 0)

  130. {
  131. list($usec, $sec) = explode(" ", microtime());
  132. $outputTimeEnd = ((float)$usec + (float)$sec);

  133. $useTime = ((float) $outputTimeEnd - (float) $outputTimeStart) * 1000000;

  134. $sleepTime = round($packetTime - $useTime);
  135. if ($sleepTime > 0)
  136. {
  137. usleep($sleepTime);
  138. }
  139. }
  140. }
  141. return true;
  142. }
  143. ?>

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