“perl"和“perl"之间的区别和“perl -w"? [英] Difference between "perl" and "perl -w"?

问题描述

我正在学习 Perl，非常新的用户.我可以知道这些 Perl 代码之间有什么区别吗.

I am learning Perl , very new user . May i know whats the difference between these Perl codes.

#!/usr/bin/perl

&

#!/usr/bin/perl -w

推荐答案

那不是 perl 代码，而是 shebang，它在 linux/unix 环境中用于告诉 shell 应该使用什么程序来运行程序文件.它在 Windows 中不起作用，但它会激活任何使用的开关.

That is not perl code, it's a shebang, which is used in a linux/unix environment as a way to tell the shell what program should be used to run the program file. It has no effect in windows, but it does activate any switches used.

-w 部分是 perl 的一个开关，告诉它激活警告.您可以通过在命令提示符下键入 perl -h 来了解有关 perl 命令行开关的更多信息.在 perldoc perlrun

The -w part is a switch for perl, telling it to activate warnings. You can learn more about perl's command line switches by typing perl -h at the command prompt. Read more in perldoc perlrun

-w 是 use warnings pragma 的旧版本，现在是首选.-w 是全局的，而 use warnings 是词法的，可以有选择地激活.

-w is the older version of the use warnings pragma, which is preferred nowadays. While -w is global, use warnings is lexical, and can be activated selectively.

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