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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