正则表达式在SunOS上使用{M，N}时未能匹配 [英] regex failed to match using {M,N} on SunOS

问题描述

我有以下示例文件和正则表达式。

testing.txt

  test aa 
a bc de 
e aa 
 ba Z 
 testing bb 
 testing ac 
  

使用egrep的正则表达式

  egrep'[] {2 ，}'testing.txt 
  

上面的正则表达式尝试在一行中查找连续的空格。
然而，返回的结果是空的。

下面的调整表达式适用于一个或多个空格。然而，这不是我想要的。

  egrep'[] +'testing.txt 
  
 
 
 
 
 传统的egrep不支持元字符，一些egrep实现支持 \ {相反，如此可移植的脚本应避免在egrep模式中使用 {，并应使用 [{] 来匹配文字<$ c这意味着，如果 grep'[$ c $> 
 
 
 ] \ {2，\}'testing.txt 不起作用 - 您最好使用Perl或GNU grep来实现您想要的功能。
 
 
 
另外， egrep'[] [] +'testing.txt 似乎只是在当前情况下的解决方法，并不会扩展，但它肯定会他请暂时与你联系。
 
I have the following sample file and regular expression.

testing.txt
testing                  aa
a bc de
e                        aa
ba                        Z
testing                  bb
testing                  ac
my regular expression using egrep
egrep '[ ]{2,}' testing.txt
The above regular expression attempts to find contiguous white spaces in a line.
However, the result returned is empty.

the regulartion expression below works for 1 or more spaces. However that is not what I want.
egrep '[ ]+' testing.txt

解决方案
If your system is old, this help reference might be describing the issue:

  
Traditional egrep did not support the {  metacharacter,  and some  egrep  implementations support \{ instead, so portable scripts should avoid { in egrep patterns and should use [{] to match a literal {.
That means, that - if grep '[ ]\{2,\}' testing.txt does not work - you are better off using Perl or GNU grep to achieve what you want.

Also, egrep '[ ][ ]+' testing.txt seems to be a workaround only in the current situation, and will not scale, but it certainly will help you for the time being.

                        
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