I need to set the an environment variable from within Perl. Ideally, I need to query a variable and then change it if it is not what is required. Specifically it is the PATH variable I want to change.
我需要在Perl中设置一个环境变量。理想情况下，我需要查询变量，然后更改它，如果它不是所需的。具体来说，它是我想要改变的PATH变量。
How do I get and set these variables?
我如何获取和设置这些变量？
3 个解决方案
#1
16
If you need to change environment variables globally and permanently, as if you set it in the control panel, then you have to muck with the registry (update: and now there are modules to do this, Win32::Env and Win32::Env::Path). Note that changing variables in the registry and "broadcasting" the change will not change the environment variables in some current processes, notably perl.exe and cmd.exe.
如果你需要全局和永久地更改环境变量，就好像你在控制面板中设置它，那么你必须使用注册表（更新：现在有模块来执行此操作，Win32 :: Env和Win32 :: Env ：：路径）。请注意，更改注册表中的变量并“广播”更改不会更改某些当前进程中的环境变量，尤其是perl.exe和cmd.exe。
If you just want to change the current process (and subsequently spawned child processes), then the global %ENV hash variable is what you want (e.g. $ENV{PATH}). See perldoc perlvar.
如果您只想更改当前进程（以及随后生成的子进程），那么全局％ENV哈希变量就是您想要的（例如$ ENV {PATH}）。见perldoc perlvar。
#2
7
$ENV{PATH}?
$ ENV {PATH}？
Keep in mind that environment variables only affect subprocesses, however. You can't run a Perl program, change %ENV, and then see that change in the parent process -- the environment does not work that way.
但请记住，环境变量只会影响子进程。您无法运行Perl程序，更改％ENV，然后在父进程中看到该更改 - 环境不能以这种方式工作。
#3
4
You can do that using the %ENV hash
你可以使用％ENV哈希来做到这一点
$ENV{PATH} = 'C:\\Windows\;D:\\Programs';
#1
16
If you need to change environment variables globally and permanently, as if you set it in the control panel, then you have to muck with the registry (update: and now there are modules to do this, Win32::Env and Win32::Env::Path). Note that changing variables in the registry and "broadcasting" the change will not change the environment variables in some current processes, notably perl.exe and cmd.exe.
如果你需要全局和永久地更改环境变量，就好像你在控制面板中设置它，那么你必须使用注册表（更新：现在有模块来执行此操作，Win32 :: Env和Win32 :: Env ：：路径）。请注意，更改注册表中的变量并“广播”更改不会更改某些当前进程中的环境变量，尤其是perl.exe和cmd.exe。
If you just want to change the current process (and subsequently spawned child processes), then the global %ENV hash variable is what you want (e.g. $ENV{PATH}). See perldoc perlvar.
如果您只想更改当前进程（以及随后生成的子进程），那么全局％ENV哈希变量就是您想要的（例如$ ENV {PATH}）。见perldoc perlvar。
#2
7
$ENV{PATH}?
$ ENV {PATH}？
Keep in mind that environment variables only affect subprocesses, however. You can't run a Perl program, change %ENV, and then see that change in the parent process -- the environment does not work that way.
但请记住，环境变量只会影响子进程。您无法运行Perl程序，更改％ENV，然后在父进程中看到该更改 - 环境不能以这种方式工作。
#3
4
You can do that using the %ENV hash
你可以使用％ENV哈希来做到这一点
$ENV{PATH} = 'C:\\Windows\;D:\\Programs';