正则表达式排除行？ [英] Regular expression to exclude lines?
问题描述
很抱歉，问一下这是一个多么微不足道的问题。也很遗憾，我手头没有现在的代码版本，但是......不管怎么说，一定有些问题
试图做负面的。每当我试图处理正则表达式时，我似乎都会陷入这些困境。
所有我想做的就是删除这些行它不包含特定的
字符串。实际上是一个用于编辑日志文件的过滤器。我可以用null找到并替换一个
的东西，但是无法弄清楚如何找到不包含
的东西。
更进一步，我想概括并使用包含
决策字符串的JavaScript变量，但首先我要担心不在线内
问题。
Sorry to ask what is surely a trivial question. Also sorry that I don''t have
my current code version on hand, but... Anyway, must be some problem with
trying to do the negative. It seems like I get into these ruts each time I
try to deal with regular expressions.
All I''m trying to do is delete the lines which don''t contain a particular
string. Actually a filter to edit a log file. I can find and replace a thing
with null, but can''t figure out how to find the lines which do not contain
the thing.
Going further, I want to generalize and use a JavaScript variable containing
the decision string, but first I need to worry about the not-within-a-line
problem.
推荐答案
Shannon Jacobs写道：
Shannon Jacobs wrote:
抱歉问什么是一个微不足道的问题。
嗯，我不认为这是微不足道的。
所有我想做的就是删除不行的行包含
特定字符串。实际上是一个用于编辑日志文件的过滤器。我可以用null找到并替换一个东西，但是不知道如何找到不包含该东西的行。
Sorry to ask what is surely a trivial question.
Hm, I don''t think it is this trivial.
All I''m trying to do is delete the lines which don''t contain a
particular string. Actually a filter to edit a log file. I can
find and replace a thing with null, but can''t figure out how to
find the lines which do not contain the thing.
这里是一个快速的过滤器，过滤掉三行中
不包含line字样的行：
alert（"） ;这是一条线。它是一个\这是一个
行" .match（/ \ n * [^ \ n] * \ n *（[^ \ n ] * [^ l] [^ i] [^ n] [^ e] [^ \ n] * \ n）* [^ \ n] * \ n * /）[1]）
但是必须有一个更好的更好的方式，IIRC有一些东西
称为负向前瞻，由JavaScript 1.5支持，
我还没有合作过。
PointedEars
Here''s a quickhack that filters out of three lines the one that
does not contain the word `line'':
alert("this is a line\nthis is a\nthis is a
line".match(/\n*[^\n]*\n*([^\n]*[^l][^i][^n][^e][^\n]*\n)*[^\n]*\n*/)[1])
But there must be a better a better way, IIRC there is something
called `negative lookahead'', supported from JavaScript 1.5 on,
which I have yet not worked with.
PointedEars
托马斯''PointedEars''Lahn< Po ****** ***@web.de>写道：
Thomas ''PointedEars'' Lahn <Po*********@web.de> writes:
Shannon Jacobs写道：
Shannon Jacobs wrote:
很抱歉，问一下这是一个多么微不足道的问题。
嗯，我不喜欢我认为这是微不足道的。
Sorry to ask what is surely a trivial question.
Hm, I don''t think it is this trivial.
我也没有。正则表达式中的负面匹配很少。
这里是快速过滤的过滤器在三行中，
不包含line一词：
警告（这是一行'，这是一个\这是一个 line" .match（/ \ n * [^ \ n] * \ n *（[^ \ n] * [^ l] [^ i] [^ n] [^ e] [^ \ n] * \ n）* [^ \ n] * \ n * /）[1]）$ b $ b
这纯粹是偶然的。如果你在前面添加一行，例如，
bad thing\\\
t这是一行，这是一个这是一条线，它匹配
包含第二行和第三行的字符串。
但是必须有一个更好的更好的方法，IIRC有一些叫做负向前瞻的东西，从JavaScript 1.5开始支持，
我还没有合作过。
Neither do I. Negative matches in regular expressions rarely are.
Here''s a quickhack that filters out of three lines the one that
does not contain the word `line'':
alert("this is a line\nthis is a\nthis is a
line".match(/\n*[^\n]*\n*([^\n]*[^l][^i][^n][^e][^\n]*\n)*[^\n]*\n*/)[1])
That''s purely accidental. If you add a line in front, e.g.,
"bad thing\nthis is a line\nthis is a\n this is a line", it matches
the string containing the second and third line.
But there must be a better a better way, IIRC there is something
called `negative lookahead'', supported from JavaScript 1.5 on,
which I have yet not worked with.
否定前瞻可能是一种更简单的方法。
艰难的方式：
/ ^（[^ l\ n] *（l [^ i] | li [^ n] | lin [^ e]））*（ [^ l\ n]）*
Negative lookahead might be an easier way to do it.
The hard way:
/^([^l\n]*(l[^i]|li[^n]|lin[^e]))*([^l\n])*
/ m
（任何l后面跟不是ine）
负向前瞻：
/ ^（[^ l\\\
] * l（？！ine））* [^ l\ n] *
/m
(any "l" is not followed by "ine")
With negative lookahead:
/^([^l\n]*l(?!ine))*[^l\n]*
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