在整个文件多行正则表达式搜索 [英] Multi-line regex search in whole file

问题描述

我发现的例子负载上使用正则表达式的文件替换文本。然而这一切都归结为两个版本：
1.迭代文件中的所有线路和应用正则表达式的每个单线
2.将整个文件。

I've found loads of examples on to to replace text in files using regex. However it all boils down to two versions:
1. Iterate over all lines in the file and apply regex to each single line
2. Load the whole file.

没有。 2是不可行使用我的文件 - 他们即将2GiB ...
至于1号：目前，这是我的做法，但我不知道......如果需要申请一个正则表达式跨越多行？

No. 2 Is not feasible using "my" files - they're about 2GiB...
As to No. 1: Currently this is my approach, however I was wondering... What if need to apply a regex spanning more than one line ?

推荐答案

这里的答案：
有没有简单的方法

Here's the Answer:
There is no easy way

我发现了一个 StreamRegex级这可能是能够做到我所期待的。照片 从我能掌握的算法：

I found a StreamRegex-Class which could be able to do what I am looking for.
From what I could grasp of the algorithm:

• 开始在文件中有一个空的缓冲区开始
• 请（
  • 添加文件的大块缓冲
  • 如果在缓冲器中的匹配
    • 标记匹配
    • 在下降从而出现在比赛结束前从缓冲区
    中的所有数据
    • Start at the beginning of the file with an empty buffer
    • do (
      • add a chunk of the file to the buffer
      • if there is a match in the buffer
        • mark the match
        • drop all data which appeared before the end of the match from the buffer

        这样，它不是以所必要的加载完整的文件 - 或者至少是加载在内存中的全部文件的机会减少...
        但是：最坏的情况是，有在整个文件不匹配 - 在这种情况下，完整的文件将被加载到内存

        That way it is not nessesary to load the full file -- or at least the chances of loading the full file in memory are reduced...
        However: Worst case is that there is no match in the whole file - in this case the full file will be loaded into memory.

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