如何从非数字字符串的替换中获得数字？
我是 perl 新手，有一个小问题：
perl 代码的一部分：
print "${data_dir}\n";
#converting directory path to unix format (replacing all backslashes with slashes)
$data_dir = ~s/\\/\//g;
print "${data_dir}\n";
输出：
C:/dev/../data
4294967295
为什么结果不同？我猜想问题出在 $data_dir 变量中，因为这适用于其他字符串，但问题可能是什么？
PS $data_dir 我是从其他模块获取的，不知道它是如何构造的。
I'm new in perl and have a little problem:
part of perl code:
print "${data_dir}\n";
#converting directory path to unix format (replacing all backslashes with slashes)
$data_dir = ~s/\\/\//g;
print "${data_dir}\n";
output:
C:/dev/../data
4294967295
Why results are different? I guess that the problem in $data_dir variable, because this works for other string, but what can be the problem?
P.S. $data_dir I'm getting from other module, and don't know how it is constructed.
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= 和 ~ 之间有一个空格。他们应该在一起=~。
您所做的是将 $data_dir 设置为等于
s/\\/\//g的补码（即 ~ 运算符），等于 4294967295。You have a space between the = and the ~. They should be together =~.
What you were doing is setting $data_dir equal to the complement (i.e. the ~ operator) of
s/\\/\//gwhich equals 4294967295.真的是“=~”里面有空格吗？
应该是“=~”，没有空格。您当前正在为 $data_dir 分配字符串的按位求反值。
您正在使用以下内容，不是吗？
使用严格；
使用警告；
Is that really "= ~" with a space in it?
It should be "=~" with no space. You are currently assigning $data_dir the bitwise negated value of the string.
Your are using the following aren't you?
use strict;
use warnings;
其他人已经回答了问题的原因 -
= ~之间的空格，应该是=~没有空格。一个宝贵的教训是始终将
use strict添加到您的脚本中；如果您这样做，您会收到如下警告：这将帮助您找出替换运算符正在
$_而不是$data_dir - 因为您没有使用绑定运算符=~将其绑定到$data_dir，而是使用了= ~。因此，要吸取的教训是：始终
使用严格- 这将有助于捕获此类情况（您可能会出现单个字符错误），并节省大量时间。顺便说一句，当使用文件路径并希望在平台之间实现可移植性时，使用 File::Spec 是通常是个好主意。
Others have already answered with the cause of the problem - the space between
= ~, which should have been=~without the space.A valuable lesson is to always add
use strictto your scripts; if you'd done so, you would have received a warning like:That would have helped you to figure out that the substitution operator was being used on
$_rather than on$data_dir- because instead of the binding operator=~binding it to$data_dir, you had= ~.So, lesson to learn: always
use strict- it'll help catch things like this, where you could have a single character wrong, and save you a lot of time.Incidentally, when working with file paths and desiring portability between platforms, using File::Spec is often a good idea.
这是因为您对 s/..../g 应用了数字运算符 (~)。
请尝试以下操作：
It is because you apply a numeric operator (~) to s/..../g.
Try the following: