php分块与断点续传文件下载代码

关于php流下载，即支持分块与断点续传文件下载的文章。

代码：

1. $dowmFile = dirname ( __FILE__ ) . ‘/Nokia – Always Here.mp3′; //要下载的文件，绝对或相对
   
2. $dowmName = ‘Nokia – Always Here.mp3′;
   
3. ob_start ();
   
4. getlocalfile ( $dowmFile, $dowmName );
   
5. flush ();
   
6. ob_flush ();
   
7. function getlocalfile($fname, $filename = ”) {
   
8. $fsize = filesize ( $fname );
   
9. header ( ‘Cache-Control: public' );
   
10. header ( ‘Pragma: public' );
    
11. header ( ‘Accept-Ranges: bytes' );
    
12. header ( ‘Connection: close' );
    
13. header ( ‘Content-Type: ‘ . MIMEType ( $fname ) );
    
14. //header(‘Content-Type: application/octet-stream');
    
15. if (isset ( $filename {0} )) {
    
16. header ( ‘Content-Disposition: attachment;filename=' . $filename );
    
17. }
    
18. if ($fp = @fopen ( $fname, ‘rb' )) {
    
19. $start = 0;
    
20. $end = $fsize;
    
21. $isRange = isset ( $_SERVER ['HTTP_RANGE'] ) && ($_SERVER ['HTTP_RANGE'] != ”);
    
22. if ($isRange) {
    
23. preg_match ( ‘/^bytes=([0-9]*)-([0-9]*)$/i', $_SERVER ['HTTP_RANGE'], $match );
    
24. $start = $match [1];
    
25. $end = $match [2];
    
26. $isset_start = isset ( $start {0} );
    
27. $isset_end = isset ( $end {0} );
    
28. if ($isset_start && $isset_end) {
    
29. //分块下载
    
30. if ($start >= $fsize || $start < 0 || $start > $end) {
    
31. $start = 0;
    
32. $end = $fsize;
    
33. } else if ($end >= $fsize) {
    
34. $end = $fsize – $start;
    
35. } else {
    
36. $end -= $start – 1;
    
37. }
    
38. } else if ($isset_start && ! $isset_end) {
    
39. //指定位置到结束
    
40. if ($start >= $fsize || $start < 0) {
    
41. $start = 0;
    
42. $end = $fsize;
    
43. } else {
    
44. $end = $fsize – $start;
    
45. }
    
46. } else if (! $isset_start && $isset_end) {
    
47. //最后n个字节
    
48. $end = $end > $fsize ? $fsize : $end;
    
49. $start = $fsize – $end;
    
50. } else {
    
51. $start = 0;
    
52. $end = $fsize;
    
53. }
    
54. }
    
55. if ($isRange) {
    
56. fseek ( $fp, $start );
    
57. header ( ‘HTTP/1.1 206 Partial Content' );
    
58. header ( ‘Content-Length: ‘ . $end );
    
59. header ( ‘Content-Ranges: bytes ‘ . $start . ‘-' . ($end + $start – 1) . ‘/' . $fsize );
    
60. } else {
    
61. header ( ‘Content-Length: ‘ . $fsize );
    
62. } www.jbxue.com
    
63. if (function_exists ( ‘fpassthru' ) && ($end + $start) == $fsize) {
    
64. fpassthru ( $fp );
    
65. } else {
    
66. echo fread ( $fp, $end );
    
67. }
    
68. } else {
    
69. header ( ‘Content-Length: ‘ . $fsize );
    
70. readfile ( $fname );
    
71. }
    
72. //@header(“Content-Type: “.mime_content_type($fname));
    
73. }
    
74. function MIMEType($fname) {
    
75. $fileSuffix = strtolower ( substr ( $fname, strrpos ( $fname, ‘.' ) + 1 ) );
    
76. switch ($fileSuffix) {
    
77. case ‘avi' :
    
78. return ‘video/msvideo';
    
79. case ‘wmv' :
    
80. return ‘video/x-ms-wmv';
    
81. case ‘txt' :
    
82. return ‘text/plain';
    
83. case ‘htm' :
    
84. case ‘html' :
    
85. case ‘php' :
    
86. return ‘text/html';
    
87. case ‘css' :
    
88. return ‘text/css';
    
89. case ‘js' :
    
90. return ‘application/javascript';
    
91. case ‘json' :
    
92. case ‘xml' :
    
93. case ‘zip' :
    
94. case ‘pdf' :
    
95. case ‘rtf' :
    
96. case ‘tar' :
    
97. return ‘application/' . $fileSuffix;
    
98. case ‘swf' :
    
99. return ‘application/x-shockwave-flash';
    
100. case ‘flv' :
     
101. return ‘video/x-flv';
     
102. case ‘jpe' :
     
103. case ‘jpg' :
     
104. return ‘image/jpeg';
     
105. case ‘jpeg' :
     
106. case ‘png' :
     
107. case ‘gif' :
     
108. case ‘bmp' :
     
109. case ‘tiff' :
     
110. return ‘image/' . $fileSuffix;
     
111. case ‘ico' :
     
112. return ‘image/vnd.microsoft.icon';
     
113. case ‘tif' :
     
114. return ‘image/tiff';
     
115. case ‘svg' :
     
116. case ‘svgz' :
     
117. return ‘image/svg+xml';
     
118. case ‘rar' :
     
119. return ‘application/x-rar-compressed';
     
120. case ‘exe' :
     
121. case ‘msi' :
     
122. return ‘application/x-msdownload';
     
123. case ‘cab' :
     
124. return ‘application/vnd.ms-cab-compressed';
     
125. case ‘aif' :
     
126. return ‘audio/aiff';
     
127. case ‘mpg' :
     
128. case ‘mpe' :
     
129. case ‘mp3′ :
     
130. return ‘audio/mpeg';
     
131. case ‘mpeg' :
     
132. case ‘wav' :
     
133. case ‘aiff' :
     
134. return ‘audio/' . $fileSuffix;
     
135. case ‘qt' :
     
136. case ‘mov' :
     
137. return ‘video/quicktime';
     
138. case ‘psd' :
     
139. return ‘image/vnd.adobe.photoshop';
     
140. case ‘ai' :
     
141. case ‘eps' :
     
142. case ‘ps' :
     
143. return ‘application/postscript';
     
144. case ‘doc' :
     
145. case ‘docx' :
     
146. return ‘application/msword';
     
147. case ‘xls' :
     
148. case ‘xlt' :
     
149. case ‘xlm' :
     
150. case ‘xld' :
     
151. case ‘xla' :
     
152. case ‘xlc' :
     
153. case ‘xlw' :
     
154. case ‘xll' :
     
155. return ‘application/vnd.ms-excel';
     
156. case ‘ppt' :
     
157. case ‘pps' :
     
158. return ‘application/vnd.ms-powerpoint';
     
159. case ‘odt' :
     
160. return ‘application/vnd.oasis.opendocument.text';
     
161. case ‘ods' :
     
162. return ‘application/vnd.oasis.opendocument.spreadsheet';
     
163. default :
     
164. if (function_exists ( ‘mime_content_type' )) {
     
165. $fileSuffix = mime_content_type ( $filename );
     
166. } else {
     
167. $fileSuffix = ‘application/octet-stream';
     
168. }
     
169. return $fileSuffix;
     
170. break;
     
171. }
     
172. }