<>Perl 如果你坚持使用“Regex”作为替代模式,将是一个很好的工具。

• l => change first char (of following match variable) to lower case
• L => change all chars (of following match variable) to lower case
• u => change single char (of following match variable) to upper case
• U => change all chars (of following match variable) to upper case

If all you care is to convert (simple/trivial!) variables and method names à la thisForExample into this_for_example.
For this a single regex like this would be sufficient:

echo  thisForExample = orThisForExample();  
| perl -pe  s/(?<=[^A-Z])([A-Z]+)(?=[^A-Z])/_L1/g; 
//output: "this_for_example = or_this_for_example();"

然而,一旦你再次希望像......这样的名字(公开的)出现。

fooURL = URLString + URL + someURLFunction();

......you。 http://www.ohchr.org。

让我们看看一下我们对此的表述:

echo  fooURL = URLString + URL + someURLFunction();  
| perl -pe  s/(?<=[^A-Z])([A-Z]+)(?=[^A-Z])/_L1/g; 
//output: "foo_url = _urlstring + _url + some_urlfunction();"

Pre脏?

And to make things even worse:
It is syntactically impossible to distinguish between a (quite common) variable name "URLString" and a class name "NSString".

Conclusion: Regex alone is pretty hack-ish and error prone for this kind of task. And simply unsufficient. And you don t want a single shell call to potentially mess up your entire code base, do you?
There is a reason why Xcode has a refactor tool that utilizes clang s grammar tree to differentiate between syntactically identical (pattern-wise at least) variable and class names. This is a problem for context free languages, not regular languages. Hence regular expressions cannot deal with it. You d need a contect free grammar to generate a language tree, etc. (and at that time you ve just started building a compiler)

另外,为什么在“核心”下使用? 如果你重新使用X条码,你可能会在奥杰C(++)或类似的一条路上重新编码,因为使用 came具有常识。 案例。 也许还有 否则的话会仇恨你,使我们有一天处理你强调的ObjC/C/...守则。

<>替代答复:

In a comment answer to Paul R you said you were basically merging two projects, one with under_scored naming, one with camelCased naming.
I d advise you then to switch your under_scored code base to camelCase. For two reasons:

1. 移至_号 案例较少的错误,反之亦然。 (前身是:在 came虫环境中,当然只有!) 如果你主要根据X条编码的精细编码处理,那也会发生同样的错误。 把它视为“可能打破的简单少法”;

2. 引用我自己的回答:

[…] I and probably pretty much everybody else would hate you for making us one day deal with your underscored ObjC/C/… code. […]

Here is a simple regex for converting under_score to camelCase:

echo  this_for_example = _leading_under_score + or_this_for_example();  
| perl -pe  s/(?<=[w])_([w])/u1/g; 
//output: "thisForExample = _leadingUnderScore + orThisForExample();"

仅需要找到<代码>[a-z][A-Z][a-z]。

恢复替代程序是trick的,不过,你计划如何将任意的上层案件换成与其较低的案件等同。

诸如<代码>([a-zA-Z][a-z]+)+?

The process could like this: You get all the names to a file, there you automatically forge the replacement, and make (automatically) sed script to change one to another.