PHP combined with redis to achieve large file deduplication

The main content of this article is to use PHP multiple processes to cooperate with the ordered collection of redis to achieve large file deduplication. Interested friends can learn about it.

1. For a large file, for example, my file is

-rw-r--r-- 1 ubuntu ubuntu 9.1G Mar 1 17:53 2018-12-awk -uniq.txt

2. Use the split command to cut into 10 small files

split -b 1000m 2018-12-awk-uniq.txt -b Cut according to bytes, supported unit m and k

3. Use 10 php processes to read the file and insert it into the ordered set structure of redis. Repeated ones cannot be inserted. , so it can play the role of deduplication

<?php
$file=$argv[1];
//守护进程
umask(0); //把文件掩码清0
if (pcntl_fork() != 0){ //是父进程，父进程退出
        exit();
}    
posix_setsid();//设置新会话组长，脱离终端
if (pcntl_fork() != 0){ //是第一子进程，结束第一子进程  
        exit();
}    
$start=memory_get_usage();
$redis=new Redis();
$redis->connect(&#39;127.0.0.1&#39;, 6379);
$handle = fopen("./{$file}", &#39;rb&#39;);
while (feof($handle)===false) {
        $line=fgets($handle);
        $email=str_replace("\n","",$line);
        $redis->zAdd(&#39;emails&#39;, 1, $email);
}

4. View the acquired data in redis

zcard emails Get the number of elements

Get elements in a certain range, such as starting from 100000 and ending at 100100

zrange emails 100000 100100 WITHSCORES

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PHP video tutorial

on the PHP Chinese website.

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