我需要将其匹配为替代命令：
whatever__MATCH_THIS__whateverwhatever__AND_THIS__whateverwhatever
我正在尝试：
sed -e 's/__\(.*\)__/\{{\1}}/g' myfile
但这是热切匹配__MATCH_THIS__whateverwhatever__AND_THIS__的，产生：
whatever{{MATCH_THIS__whateverwhatever__AND_THIS}}whateverwhatever
但我想要：
whatever{{MATCH_THIS}}whateverwhatever{{AND_THIS}}whateverwhatever
如何在匹配部分中指定要排除的字符串？我知道如何排除一个字符（例如[^a]），但不知道如何排除一个字符串。
您需要的是一个非贪婪的正则表达式，但不幸的是 sed 不允许这样做。但是，它可以在 perl 中完成。
perl -pe 's|__(.*?)__|{{$1}}|g' <myfile
星号后面的问号表示匹配器是非贪婪的，因此不是采用它可以找到的最长匹配字符串，而是采用最短的匹配字符串。
希望有帮助。
如果你想把它放在 perl 脚本中而不是在命令行上运行，那么这样的事情就可以完成：
#! /usr/bin/perl -w
use strict; # Habit of mine
use 5.0100; # So we can use 'say'
# Save the matching expression in a variable.
# qr// tells us it's a regex-like quote (http://perldoc.perl.org/functions/qr.html)
my $regex = qr/__(.*?)__/;
# Ordinarily, I'd write this in a way I consider to be less perl-y and more readable.
# What it's doing is reading from the filename supplied on STDIN and places the
# contents of the file in $_. Then it runs the substitution on the string, before
# printing out the result.
while (<>) {
$_ =~ s/$regex/{{$1}}/g;
say $_;
}
用法很简单：
./regex myfile
whatever{{MATCH_THIS}}whateverwhatever{{AND_THIS}}whateverwhatever
它是 Perl，有一百万零一种方法可以做到！
sed ':k s/__/{{/;s/__/}}/;tk' file
输入：
whatever__MATCH_THIS__whateverwhatever__AND_THIS__whateverwhatever
blah__XXX_XX__blah_blah_blah__XX_XXX__whateverwhatever
输出：
whatever{{MATCH_THIS}}whateverwhatever{{AND_THIS}}whateverwhatever
blah{{XXX_XX}}blah_blah_blah{{XX_XXX}}whateverwhatever
sed不支持 PCRE 好东西，例如非贪婪运算符
我能够通过以下变体解决您的情况：
echo 'whatever__MATCH_THIS__whateverwhatever__AND_THIS__whateverwhatever' |
sed -e 's/__\([^_]\+_[^_]\+\)__/\{{\1}}/g'
whatever{{MATCH_THIS}}whateverwhatever{{AND_THIS}}whateverwhatever
虽然很明显，一种使用方法sed不是完成这项工作的最佳工具。我已经评论了代码以查看会发生什么，因为它似乎有点困惑：
sed -n '
## Insert a newline just before each "__". This is the most
## important instruction of all the script. The game is that
## newline character is the only want that sed cannot find in
## a line of data, so use it to know where there will be "__"
## to change. For each part changed the script will save it
## in hold space, but due to constraints of those (only two
## spaces) I will have to play deleting and recovering data
## several times between both.
s/__/\n&/g
## Save in hold space all data until first newline.
## So it means, just before the first "__" of the line.
h ; s/\n.*$// ; x
## Remove that part just saved in hold space.
s/^[^\n]*\n//
## Set a label to jump it later.
:a
## This is end condition. When not found any newline
## in the pattern space means that there are no more "__" to
## process, so get all data saved in hold space, print
## it and leave hold space empty ready for next line of
## the input file.
/^[^\n]\+$/ {
g
p
x
s/^.*$//
x
b
}
## This part of code will process next two input lines.
## First one has the first pair of "__" and second one has
## the end pair, so substitute to each respective curly
## braces.
s/__/{{/
## Once the substitution has been done, save it adding to
## hold space.
## I add all the line but only want to keep until first newline.
## I delete two of them because "H" command adds it one by itself.
H ; x ; s/\n// ; s/\n.*$// ; x
## Delete part just processed and saved in hold space.
s/^[^\n]*\n//
## Repeat same process for end pair of "__"
s/__/}}/
H ; x ; s/\n// ; s/\n.*$// ; x
s/^[^\n]*\n//
## Goto label "a"
ba
' infile
粘贴并从命令行运行它，只要它产生两行：
whatever{{MATCH_THIS}}whateverwhatever{{AND_THIS}}whateverwhatever
exten => s,n,ExecIf($[${amacode} == 1]?Set(rateparams_view={{INCOMING_RATEPARAMS_VIEW}}):Set(rateparams_view={{OUTGOING_RATEPARAMS_VIEW}}))
这可能对您有用（GNU sed）：
sed -r 's/__([^_]+(_[^_]+)*)__/{{\1}}/g' file
或者，也许更容易理解：
sed -r 's/__/\n/g;s/\n([^\n]*)\n/{{\1}}/g;s/\n/__/g' file
这适用于我的 Windows XP 笔记本电脑
input command
echo whatever__MATCH_THIS__whateverwhatever__AND_THIS__whateverwhatever|sed -f a.sed
output
whatever{{__MATCH_THIS__}}whateverwhatever{{__AND_THIS__}}whateverwhatever
where a.sed is this
/__MATCH_THIS__/{
/__AND_THIS__/{
s/__MATCH_THIS__/\{\{__MATCH_THIS__\}\}/
s/__AND_THIS__/\{\{__AND_THIS__\}\}/
}
}