perl - 如何在 perl 脚本退出之前运行一段代码

Question

在我的脚本中，我需要从磁盘文件中加载一些信息，并且在脚本运行期间，信息可能会被更改。为了保持磁盘中文件的一致性并且它在内存副本中，我需要
每当信息在内存中更改或定期写入时，将信息写回磁盘
回到磁盘或在脚本退出时将它们写回，这是首选，因为它会节省大量 IO 时间并使脚本响应。

所以就像标题一样，我的问题是 perl 是否有一些机制可以满足我的需求？

Answer 1

我想你正在寻找 END block :

END {
    # cleanup
}

An END code block is executed as late as possible, that is, after perl has finished running the program and just before the interpreter is being exited, even if it is exiting as a result of a die() function. (But not if it's morphing into another program via exec, or being blown out of the water by a signal--you have to trap that yourself (if you can).) You may have multiple END blocks within a file--they will execute in reverse order of definition; that is: last in, first out (LIFO). END blocks are not executed when you run perl with the -c switch, or if compilation fails.