Detailed explanation of how PHP implements breakpoint resumption and file splitting sample code

<?php

$fp = fopen("socket.zip", "rb");
$filesize = 10;
$i = 0;
$no = 1;
while(!feof($fp))
{
  $file = fread($fp, $filesize);

  $fp2 = fopen("./split/socket.port".sprintf("%04d",$no).".".$i."-".($i+$filesize).".tmp", "wb");
  fwrite($fp2, $file, $filesize);
  fclose($fp2);
  $i+=$filesize+1;
$no++;
}

fclose($fp);

<?php
$filelist = glob(&#39;./split/*socket*.tmp&#39;);
$filesize = 10;

//print_r($filelist);
$mergeFileName = &#39;merg.zip&#39;;

unlink($mergeFileName);
  $fp2 = fopen($mergeFileName,"w+");
foreach($filelist as $k => $v)
{
  $fp = fopen($v, "rb");
   $content = fread($fp, $filesize);

   fwrite($fp2, $content, $filesize);
   unset($content);
   fclose($fp);
   echo $k,"\n";
}
  fclose($fp2);

<?php 
ini_set("memory_limit", "50M");//必须的，根据你环境的实际情况尽量大，防止报错 
ini_set("max_execution_time", "100"); 
//file_exists() 函数检查文件或目录是否存在，存在则返回 true，否则返回 false。 
//fread() 函数读取文件（可安全用于二进制文件）。fread() 从文件指针 file 读取最多 length 个字节。 
//filesize() 函数返回指定文件的大小（字节）。本函数的结果会被缓存。请使用 clearstatcache() 来清除缓存。 
$orgFile = &#39;Fireworks8-chs.exe&#39;;//源文件 
$cacheFileName = &#39;vbcache&#39;;//分割成的临时文件块 
function cutFile($fileName,$block) {//分割 
global $cacheFileName; 
if (!file_exists($fileName)) return false; 
$num = 1; 
$file = fopen($fileName, &#39;rb&#39;); 
while ($content = fread($file,$block)) { 
$cacheFile = $cacheFileName . $num++ . &#39;.dat&#39;; 
$cfile = fopen($cacheFile, &#39;wb&#39;); 
fwrite($cfile, $content); 
fclose($cfile); 
} 
fclose($file); 
} 
function mergeFile($targetFile) {//合并 
global $cacheFileName; 
$num = 1; 
$file = fopen($targetFile, &#39;wb&#39;); 
while ($num > 0) { 
$cacheFile = $cacheFileName . $num++ . &#39;.dat&#39;; 
if (file_exists($cacheFile)) { 
$cfile = fopen($cacheFile, &#39;rb&#39;); 
$content = fread($cfile, filesize($cacheFile)); 
fclose($cfile); 
fwrite($file, $content); 
} 
else { 
$num = -1; 
} 
} 
fclose($file); 
} 
//调用 
cutFile($orgFile, 10 * pow(2,20)); //10 * pow(2,20) 就等于 10M pow() 函数返回 x 的 y 次方 
mergeFile(&#39;ok.exe&#39;); 
?>