PHP 内存泄露重现 include 匿名函数技术

maybe yes 发表于 2022-05-01 10:11


这个是 include 或者是 require 对于匿名函数的内存泄露大坑。

很多市面上的 PHP 教程都说 include require 相当于把代码复制到那个位置,从这个代码示例验证来看,其实不是这样的!

while (true) {
        if ($i%1000 == 0) {
                echo memory_get_usage()."\n";
        $b = 'b';
        $render_func = function($d) use ($b) {
                $u = 1;
                //test3.php $x = function(){};
                require 'test3.php';


maybe yes 发表于 2022-04-23 12:48


通过支付宝的 通信大数据行程卡 下面有个 行程卡使用说明,点进去大家都会发现,真正的官网是 xc.caict.ac.cn。

支付宝修改了行程卡的 UI,这样,如果你通过官方渠道去获取了行程卡的截图,发现和支付宝的不一样,字体不一样。因为普通大众只知道支付宝,所以会认为官方的是假的,这样随意篡改官方 UI 的行为真的要严惩。

祸国殃民的 APP!



How to Increase Number of Open Files Limit in Linux技术

maybe yes 发表于 2022-04-17 17:43


Find Linux Open File Limit
The value is stored in:

# cat /proc/sys/fs/file-max

The number you will see, shows the number of files that a user can have opened per login session. The result might be different depending on your system.

For example on a CentOS server of mine, the limit was set to 818354, while on Ubuntu server that I run at home the default limit was set to 176772.

If you want to see the hard and soft limits, you can use the following commands:

Check Hard Limit in Linux
# ulimit -Hn

Check Soft Limits in Linux
# ulimit -Sn

To see the hard and soft values for different users, you can simply switch user with “su” to the user which limits you want to check.

For example:

# su marin
$ ulimit -Sn

$ ulimit -Hn

How to Check System wide File Descriptors Limits in Linux
If you are running a server, some of your applications may require higher limits for opened file descriptors. A good example for such are MySQL/MariaDB services or Apache web server.

You can increase the limit of opened files in Linux by editing the kernel directive fs.file-max. For that purpose, you can use the sysctl utility.

Sysctl is used to configure kernel parameters at runtime.

For example, to increase open file limit to 500000, you can use the following command as root:

# sysctl -w fs.file-max=500000
You can check the current value for opened files with the following command:

$ cat /proc/sys/fs/file-max
With the above command the changes you have made will only remain active until the next reboot. If you wish to apply them permanently, you will have to edit the following file:

# vi /etc/sysctl.conf
Add the following line:

Of course, you can change the number per your needs. To verify the changes again use:

# cat /proc/sys/fs/file-max
Users will need to logout and login again for the changes to take effect. If you want to apply the limit immediately, you can use the following command:

# sysctl -p
Set User Level Open File limits in Linux
The above examples, showed how to set global limits, but you may want to apply limits per user basis. For that purpose, as user root, you will need to edit the following file:

# vi /etc/security/limits.conf
If you are a Linux administrator, I suggest you that you become very familiar with that file and what you can do to it. Read all of the comments in it as it provides great flexibility in terms of managing system resources by limiting users/groups on different levels.

The lines that you should add take the following parameters:

<domain>        <type>  <item>  <value>
Here is an example of setting a soft and hard limits for user marin:

## Example hard limit for max opened files
marin        hard nofile 4096
## Example soft limit for max opened files
marin        soft nofile 1024
Final thoughts
This brief article showed you a basic example of how you can check and configure global and user level limits for maximum number of opened files.

While we just scratched the surface, I highly encourage you to have a more detailed look and read regarding /etc/sysctl.conf and /etc/security/limits.conf and learn how to use them. They will be of great help for you one day.


maybe yes 发表于 2022-04-16 17:58


假设 archive.tgz 大小约 2M,里面有 1000 个小文件,其中一个文件名字为 a.txt,我们为了拿到 a.txt,则需要执行下面的命令!

tar zxOf archive.tgz a.txt

现在的问题是,上面的命令存在性能问题,耗时有时候会高达 20s。如何加快这个速度呢?



maybe yes 发表于 2022-04-12 15:52





2022-05-21 21:29:45 1653139785 0.004169