How to delete lines before and after matching pattern

Question

i have a file like below. I want to search pattern ABC_DATA as a variable and after match, i want to delete from first previous "multipath" line to the line including "}" character. "}" could be after or in the same line with ABC_DATA.

SAMPLE OUTPUT

multipaths {
multipath {
wwid 360000970000267600432533030353944
alias ABC_DATA_11
}
multipath {
wwid 360000970000267600432533030353945
alias DEF_DATA_11
}
multipath {
wwid 360000970000267600432533030353946
alias ABC_DATA_12 }

multipath {
wwid 360000970000267600432533030353943
alias DEF_DATA_10
}
}

EXPECTED OUTPUT

multipaths {
multipath {
wwid 360000970000267600432533030353945
alias DEF_DATA_11
}
multipath {
wwid 360000970000267600432533030353943
alias DEF_DATA_10
}
}

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score 3 · Accepted Answer · edited Dec 02 '20 at 01:55

3

$ awk -v RS='multipath\\s*{[^}]*ABC_DATA[^}]*}\\s*(\n|$)' -v ORS= '1' file
multipaths {
multipath {
wwid 360000970000267600432533030353945
alias DEF_DATA_11
}
multipath {
wwid 360000970000267600432533030353943
alias DEF_DATA_10
}
}

edited Dec 02 '20 at 01:55

Michael

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answered Dec 02 '20 at 00:29

Ed Morton

188,023
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Can you explain this a bit? What is setting `ORS='1'` doing? – dawg Dec 02 '20 at 03:14
Thanks Ed, it works :). i will pass ABC_DATA as first argument of bash script. So, awk -v RS='multipath\\s*{[^}]*'$1'[^}]*}\\s*(\n|$)' -v ORS= '1' /etc/multipath.test is final solution for me. – solmyr Dec 02 '20 at 06:14
1

@Ed Moton. +1. Great regexp: --> remove all unwanted data and `awk` show the `expected output`! – Carlos Pascual Dec 02 '20 at 11:39
1

@dawg I'm not setting ORS to 1, I'm setting ORS to null so awk doesn't add a newline when outputting each record, and then the `1` at the end is just the usual shorthand for `{print}`. – Ed Morton Dec 02 '20 at 14:22
@solmyr make that `RS='multipath\\s*{[^}]*'"$1"'[^}]*}\\s*(\n|$)'` so that `$1` is quoted `"$1"` to avoid globbing, filename expansion, etc. when it's referenced there. – Ed Morton Dec 02 '20 at 14:24
1

@EdMorton: Head smack. Of course. I was so fixated on `ORS='1'` that I did not notice the space! It is `ORS= '1'` (note space) so that `'1'` is the program... – dawg Dec 02 '20 at 14:33

dawg · Answer 2 · 2020-12-02T12:44:49.617

0

Given your example, you can use this perl:

$ perl -0777 -lpe 's/\bmultipath\h+\{[^{}]*ABC_DATA[^{}]*}\s*//g' file
multipaths {
multipath {
wwid 360000970000267600432533030353945
alias DEF_DATA_11
}
multipath {
wwid 360000970000267600432533030353943
alias DEF_DATA_10
}
}

edited Dec 02 '20 at 12:44

answered Dec 02 '20 at 01:09

dawg

98,345
23
131
206

1

Should you use `-lpe`, so you don't need `print` ? – Philippe Dec 02 '20 at 09:21

score 0 · Answer 3 · answered Dec 02 '20 at 14:59

Using sed, not really readable but definitely possible:

sed '
   /^multipath {/ {
     :l
     /alias ABC_DATA/ {
       :f
       /}/ d
       N
       b f
     }
     /}/ b
     N
     b l
  }' input

or as a single line:

sed '/^multipath {/{:l; /alias ABC_DATA/{:f /}/d;N;bf};/}/b;N;bl};' input

How to delete lines before and after matching pattern

3 Answers3