为什么我的perl替换不起作用？ [英] Why is my perl replace not working?

问题描述

 <$> 
 
 c $ c> perl -pi -w -e's / onclick = \img = document.getElementById（\'img_1\'）\; img.style.display =（img.style.display == ''''''''''''''''''''''''';''''）; return false//'test.html 
   
 
  perl -pi -w -e's / b 
 
 
 onclick =img = document.getElementById（'img_1'）; img.style.display =（img.style.display =='none'？'block'：'none'）; return false//'test.html 
  
我的目标是取代 onclick =img = document.getElementById（' img_1'）; img.style.display =（img.style.display =='none'？'block'：'none'）; return false文件中没有任何内容的test.html 。我在搞什么？ 
 
 
 
我一直在得到错误： -sh：在意外标记附近出现语法错误）``我不禁但感觉是因为我的一些愚蠢的逃避。请帮助我。
解决方案
 [您没有指定您正在构建命令的shell。我将假设 sh 或 bash 。 ] 
 
 
 
 
问题＃1：将文本转换为正则表达式模式
 
 
很多字符在正则表达式中有特殊的含义。在你使用的那些中，（，），。和？是特别的。 
 
 
 
如果您想匹配 
 
 
  onclick =img = document.getElementById（'img_1'）; img.style.display =（img.style.display =='none'？'block'：'none'）; return false
  
您需要使用模式
  onclick =img = document\.getElementById\（'img_1'\）; img\.style\.display = \（img\.style\.display =='none' \'block'：'none'\）; return false
  
是 
 
 
  s / onclick =img = document\.getElementById\（'img_1'\）; img\ .style \.display = \（img\.style\.display =='none'\？'block'：'none'\）; return false// 
  
 
 
 
 
 
 
问题2：将文本（Perl程序）转换为shell文本 h2> 
 
 
这是您询问的问题。
 
 
 
由单引号（'）引用的部分在下一个单引号（无条件地）结束，因此以下错误： 
 
 
  echo'foo\\'''bar'＃第三个''不匹配。 
  
如果您想输出 foo'bar ，您可以使用 
 
 
  echo'foo'\\''bar'＃foo，'的连接和酒吧。 
  
  foo 和 bar 用单引号引用，单引号使用 \ 进行转义。  \ 在这里工作，因为它在单引号之外。
所以，课程基本上使用'\''而不是'在单引号内。
 
 
 
你想把下面的程序传给Perl： 
 
 
  s / onclick =img = document\.getElementById\（'img_1 '\）; img\.style\.display = \（img\.style\.display =='none'\？'block'：'none'\）; return false/ / 
  
为此，您需要创建一个shell文字来产生正确的参数，意思是我们希望用单引号括起整个单词，并且避开现有的单引号。我们得到以下结果： 
 
 
 's / onclick =img = document \.getElementById\（'\'' img_1'\''\）; img\.style\.display = \（img\.style\.display =='\''none'\''\？'\\ ''''''''''''''）; return false//'
  
因此，整个命令将是 
 
 
  perl -i -wpe's / onclick = img = document \.getElementById\（'\''img_1'\''\）; img\.style\.display = \（img\.style\.display == '\\''''''''''''''''''''''''''：'\'''）; return false//'test.html 
  
 
I have the following perl search and replace : 


With Escapes :
perl -pi -w -e 's/ onclick=\"img=document.getElementById(\'img_1\')\; img.style.display = (img.style.display == \'none\' ? \'block\' : \'none\');return false"//' test.html 
Without Escapes : 
perl -pi -w -e 's/ onclick="img=document.getElementById('img_1'); img.style.display = (img.style.display == 'none' ? 'block' : 'none');return false"//' test.html 
My objective is to replace onclick="img=document.getElementById('img_1'); img.style.display = (img.style.display == 'none' ? 'block' : 'none');return false" with nothing in the file test.html. What am I messing up? 

I keep on getting the error : -sh: syntax error near unexpected token)'` which I cannot help but feel is because of some stupid escaping on my part. Please help me out.
解决方案
[ You didn't specify for which shell you are building the command. I'm going to assume sh or bash. ]



Problem #1: Converting text into a regex pattern

Many characters have a special meaning in regex patterns. Among those you used, (, ), . and ? are special. These need to be escaped.

If you want to match
onclick="img=document.getElementById('img_1'); img.style.display = (img.style.display == 'none' ? 'block' : 'none');return false"
You need to use the pattern
onclick="img=document\.getElementById\('img_1'\); img\.style\.display = \(img\.style\.display == 'none' \? 'block' : 'none'\);return false"
So your Perl code is
s/onclick="img=document\.getElementById\('img_1'\); img\.style\.display = \(img\.style\.display == 'none' \? 'block' : 'none'\);return false"//




Problem #2: Converting text (a Perl program) into a shell literal

This is the problem you asked about.

Sections quoted by single quotes ("'") end at the next single quote (unconditionally), so the following is wrong:
echo 'foo\'bar'   # Third "'" isn't matched.
If you wanted to output "foo'bar", you could use
echo 'foo'\''bar'   # Concatenation of "foo", "'" and "bar".
foo and bar are quoted by single quotes, and the single quote is escaped using \. \ works here because it's outside of single quotes.

So, the lesson is basically use '\'' instead of ' inside single quotes.

you want to pass the following program to Perl:
s/onclick="img=document\.getElementById\('img_1'\); img\.style\.display = \(img\.style\.display == 'none' \? 'block' : 'none'\);return false"//
To do so, you'll need to create a shell literal that produces the correct argument, meaning we want to surround the whole with single quotes and escape the existing single quotes. We get the following:
's/onclick="img=document\.getElementById\('\''img_1'\''\); img\.style\.display = \(img\.style\.display == '\''none'\'' \? '\''block'\'' : '\''none'\''\);return false"//'
As such, the entire command would be
perl -i -wpe's/onclick="img=document\.getElementById\('\''img_1'\''\); img\.style\.display = \(img\.style\.display == '\''none'\'' \? '\''block'\'' : '\''none'\''\);return false"//' test.html


                        
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