Question

我在日志中有什么。

    ---POLICIES WITH 172.25.22.16 AS SOURCE ADDRESS---
    ---POLICIES WITH 172.25.22.16 AS DESTINATION ADDRESS---
    ---POLICIES WITH 172.25.22.17 AS SOURCE ADDRESS---
    some output
    ---POLICIES WITH 172.25.22.17 AS DESTINATION ADDRESS---
    ---POLICIES WITH 172.25.22.18 AS SOURCE ADDRESS---
    some output
    ---POLICIES WITH 172.25.22.18 AS DESTINATION ADDRESS---
    ---POLICIES WITH 172.25.22.19 AS SOURCE ADDRESS---

需要什么

    ---POLICIES WITH 172.25.22.16 AS SOURCE ADDRESS---
    None
    ---POLICIES WITH 172.25.22.16 AS DESTINATION ADDRESS---
    None
    ---POLICIES WITH 172.25.22.17 AS SOURCE ADDRESS---
    some output
    ---POLICIES WITH 172.25.22.17 AS DESTINATION ADDRESS---
    None
    ---POLICIES WITH 172.25.22.18 AS SOURCE ADDRESS---
    some output
    ---POLICIES WITH 172.25.22.18 AS DESTINATION ADDRESS---
    None
    ---POLICIES WITH 172.25.22.19 AS SOURCE ADDRESS---
    None

我尝试了sed's：--- \ n ---：---- \ nNone \ n --- /：g'，但没有这样做。仅在下一行以---

开头时，我才需要对所有以---结尾的行进行替换。

Answer 1

我会写

awk '
  /^---/ && prev ~ /^---/ {print "None"}
  {print; prev = $0}
  END {if (/^---/) print "None"}
' file

一些干燥器

awk '
  function none() {if ($0 ~ /^---/ && prev ~ /^---/) {print "None"}}
  {none(); print; prev = $0}
  END {none()}
' file

Answer 2

您可以使用GNU sed（对于-E，-z并将\n识别为换行符）进行以下操作：

$ sed -Ez 's/(---\n)(---|$)/\1None\n\2/g' file
---POLICIES WITH 172.25.22.16 AS SOURCE ADDRESS---
None
---POLICIES WITH 172.25.22.16 AS DESTINATION ADDRESS---
None
---POLICIES WITH 172.25.22.17 AS SOURCE ADDRESS---
some output
---POLICIES WITH 172.25.22.17 AS DESTINATION ADDRESS---
None
---POLICIES WITH 172.25.22.18 AS SOURCE ADDRESS---
some output
---POLICIES WITH 172.25.22.18 AS DESTINATION ADDRESS---
None
---POLICIES WITH 172.25.22.19 AS SOURCE ADDRESS---
None

或用于多字符RS和gensub（）的GNU awk：

$ awk -v RS='^$' -v ORS= '{$0=gensub(/(---\n)(---|$)/,"\\1None\n\\2","g")}1' file
---POLICIES WITH 172.25.22.16 AS SOURCE ADDRESS---
None
---POLICIES WITH 172.25.22.16 AS DESTINATION ADDRESS---
None
---POLICIES WITH 172.25.22.17 AS SOURCE ADDRESS---
some output
---POLICIES WITH 172.25.22.17 AS DESTINATION ADDRESS---
None
---POLICIES WITH 172.25.22.18 AS SOURCE ADDRESS---
some output
---POLICIES WITH 172.25.22.18 AS DESTINATION ADDRESS---
None
---POLICIES WITH 172.25.22.19 AS SOURCE ADDRESS---
None

但是我强烈建议您使用以下POSIX awk来提高可移植性，而不是一次将整个文件读入内存，并且如果需要进行任何更改，可以轻松增强它：

$ cat tst.awk
/^---/ { if (NR>1) prt(); hdr=$0; next }
{ txt = txt ORS $0 }
END { prt() }
function prt() {
    print hdr (txt=="" ? ORS "None" : txt)
    hdr = txt = ""
}

$ awk -f tst.awk file
---POLICIES WITH 172.25.22.16 AS SOURCE ADDRESS---
None
---POLICIES WITH 172.25.22.16 AS DESTINATION ADDRESS---
None
---POLICIES WITH 172.25.22.17 AS SOURCE ADDRESS---
some output
---POLICIES WITH 172.25.22.17 AS DESTINATION ADDRESS---
None
---POLICIES WITH 172.25.22.18 AS SOURCE ADDRESS---
some output
---POLICIES WITH 172.25.22.18 AS DESTINATION ADDRESS---
None
---POLICIES WITH 172.25.22.19 AS SOURCE ADDRESS---
None

Answer 3

使用awk

awk '{
        if($0 ~ /^-{3}/){
            if(header==1){
                print "None"
            }; 
            header = 1
        }else{
            header = 0
        }
     }1
     END{
        if(header){
            print "None"
        }
     }' <input>

Shorter：

awk '!/^-{3}/{header=0;print;next}header{print "None"}{header=1}1;END{if(header){print "None"}}' <input>

Answer 4

这可能对您有用（GNU sed）：

sed -e ':a;/^---.*---$/{${aNone' -e 'b};n;//!b;iNone' -e 'ba}' file

如果当前行以---开始和结束，并且它是文件的最后一行，请附加字符串None。否则，打印当前行并获取下一行，如果该行也以---，插入 None开始和结束并重复。

用sed替换多行字符串

4 个答案: