在两个字符串模式之间替换多次出现的字符 [英] Replacing multiple occurrences of a char between two string patterns

问题描述

我有一个包含以下内容的文件 1.txt

I have a file 1.txt with below content

F1,F2,[as1,as2],[as3,as4]

F1,F2,[as1,as2],[as3,as4]

F3,F4,F5,[as5,as6]

F3,F4,F5,[as5,as6]

我需要在 perl 中编写一个正则表达式，以便我应该将 [' 和 '] 之间的分隔符 ',' 更改为 | .

I require to write a regex in perl so that I should change the delimiter ',' inbetween [' and '] to | .

我在下面尝试过，但没有奏效.

I tried below, but it did not work.

@qr = $st = /\{(.*)(\|)+\}/;

其中 $st 具有输入字符串.

where $st has the input string.

推荐答案

对于早于 Perl 5.14 的 Perl 版本，你不能不使用像这样的正则表达式

For the versions of Perl older than Perl 5.14, you can't but use a regex like

echo "[as1,as2,as3],[as4,as5]" | perl -lpe 's/(?:\[|\G(?!^))[^]]*?\K,/|/g'

查看在线演示.

模式详情:

• (?:\[|\G(?!^)) - 文字 [ 或前一个匹配的结尾 (\G(?!^))
• [^]]*? - 除 ] 之外的零个或多个字符，尽可能少地匹配
• \K - 删除整个匹配值
• , - 匹配中的逗号(被替换为 |).

• (?:\[|\G(?!^)) - either a literal [ or the end of the previous match (\G(?!^))
• [^]]*? - zero or more chars other than ], as few as possible, are matched
• \K - the whole match value is dropped
• , - a comma lands in the match (that is replaced with |).

对于 Perl 5.14 和更新版本(r 修饰符出现的地方)，您可以将 [...] 子字符串与 \[[^][]+] 正则表达式(匹配 [，然后是除 [ 和 ] 之外的 1+ 个字符，然后 ]) 并在这些匹配项中执行替换:

For Perl version 5.14 and newer (where r modifier appeared), you may match the [...] substrings with \[[^][]+] regex (that matches [, then 1+ chars other than [ and ], and then ]) and perform the replacements inside these matches:

echo "F1,F2,[as1,as2],[as3,as4]" | perl -lpe 's/(\[[^][]+])/$1=~s#,#|#gr/ge'
# => F1,F2,[as1|as2],[as3|as4]

查看在线演示.

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