从字符串中提取子串与多个特殊字符使用桑达 [英] Extracting Substring from String with Multiple Special Characters Using Sed

问题描述

我有这样一行文本文件：

 ＆LT; D​​IV ID =page_footer＆GT;＆LT; D​​IV＆GT;＆LT ;?打印（任何短语中的人物可以去这里！'）; ？＆GT;＆LT; / DIV＆GT;＆LT; / DIV＆GT;
 

和我想用 SED 或 AWK 来提取上述单引号之间的字符串，因此只是打印...

 任何短语中的人物可以去这里！
 

我要分隔那句我已经在上面，单引号后开始，并在单引号后面紧跟一个括号，然后分号结尾。与捕获组以下sed命令似乎并没有对我的工作。建议？

  sed的'/ ^＆LT; D​​IV ID =page_footer＆GT;＆LT; D​​IV＆GT;＆LT ;?打印（\\'\\（\\ + \\）\\'）; /秒// \\ 1 / P'/home/foobar/testfile.txt
 

解决方案

错误将使用切割仿

 的greppage_footer/home/foobar/testfile.txt |切-d'-f2
 

它会出差错字符串中单引号。计数单​​引号的数量将首先从一个简单的改变这一个过于复杂的解决方案。

用sed的一个解决方案是更好的：除去一切直到最后一个人后的第一个单引号和一切。字符串中的单引号变得混乱时，先关闭sed的参数用单引号，逃避单引号，然后再次打开一个sed字符串：

 的grep page_footer /home/foobar/testfile.txt | SED -e的/ [^'\\''] * //'-e'S / [^'\\''] * $ //'
 

这是不完整的解决方案，你要删除的第一个/最后报价，以及：

 的grep page_footer /home/foobar/testfile.txt | SED -e的/ [^'\\''] *'\\''//'-e'S /'\\''[^'\\''] * $ //'
 

写作双引号字符串的SED参数和使用。通配符单引号匹配将使该行更短：

 的grep page_footer /home/foobar/testfile.txt | SED -eS /^[^\\']*.//-ES /.[^\\']*$//
 

I have a text file with a line that reads:

<div id="page_footer"><div><? print('Any phrase's characters can go here!'); ?></div></div>

And I'm wanting to use sed or awk to extract the substring above between the single quotes so it just prints ...

Any phrase's characters can go here!

I want the phrase to be delimited as I have above, starting after the single quote and ending at the single-quote immediately followed by a parenthesis and then semicolon. The following sed command with a capture group doesn't seem to be working for me. Suggestions?

sed '/^<div id="page_footer"><div><? print(\'\(.\+\)\');/ s//\1/p' /home/foobar/testfile.txt

解决方案

Incorrect would be using cut like

 grep "page_footer" /home/foobar/testfile.txt | cut -d "'" -f2

It will go wrong with single quotes inside the string. Counting the number of single quotes first will change this from a simple to an over-complicated solution.

A solution with sed is better: remove everything until the first single quote and everything after the last one. A single quote in the string becomes messy when you first close the sed parameter with a single quote, escape the single quote and open a sed string again:

grep page_footer /home/foobar/testfile.txt | sed -e 's/[^'\'']*//' -e 's/[^'\'']*$//'

And this is not the full solution, you want to remove the first/last quotes as well:

grep page_footer /home/foobar/testfile.txt | sed -e 's/[^'\'']*'\''//' -e 's/'\''[^'\'']*$//'

Writing the sed parameters in double-quoted strings and using the . wildcard for matching the single quote will make the line shorter:

grep page_footer /home/foobar/testfile.txt | sed -e "s/^[^\']*.//" -e "s/.[^\']*$//"

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