Shell Script: Want to delete two consecutive lines matching pattern from specific line

Question

I want to delete specific two consecutive lines matching patterns from specific line from a file.

For e.g. file contents are like below.

Line1: a
Line2: b
Line3: c
Line4: Name: 123
Line5:  xyz
Line6: Name: 456
Line7:  abc

I want to find the lines starting from line 4, matching 1st line pattern starting with "Name: " and matching 2nd line pattern starting with whitespace and delete the two consecutive lines.

Any efficient way to do this in shell using sed or something else?

To be a bit more clear, I want to remove signing/checksum information from the MANIFEST.MF.

Sample MANIFEST.MF like below: From the below manifest file, I want to remove the entry "Name: ". where "Name: " entry can be in one line or 2(or more) lines.

Initially my solution was like find the first "Name: " entry followed by "SHA-256-Digest: " entry and delete to the end of the file. Unfortunately this solution has a problem of removing one needed entry in the middle. For e.g. "NetBeans-Simply-Convertible: " is also being removed.

So, now I want to remove "Name: " entry if available in 1 line or entry spanned across 2 or more lines. But I should not lose entries like "NetBeans-Simply-Convertible: " while removing "Name: " entries.

Already I am removing "SHA-256-Digest: " entries with the below command on file with sed -i "/^\SHA-256-Digest: /d" $manifest_file

---

Manifest-Version: 1.0
Version-Info: ....

Name: com/abc/xyz/pqr/client/relationship/message/notifier/Relati
 onshipUpdateNotifierFactory.class
SHA-256-Digest: cSSyk6Y2L2F9N6FPtswUkxjF2kelMkGe4bFprcQ+3uY=

Name: com/abc/xyz/pqr/client/relationship/ui/BaseRelationshipView
 $5.class
SHA-256-Digest: w9HgRjDuP024U4CyxeKPYFe6rzuzxZF3b+9LVG36XP8=

Name: com/abc/xyz/pqr/client/impl/MofRelationshipAgentImpl.class
SHA-256-Digest: GwIBIU+UdPtjyRhayAVM90Eo+SwCT/kP65dI59adEnM=

Name: com/abc/xyz/pqr/client/settings/ConvertibleProperties.class
NetBeans-Simply-Convertible: {com/abc/xyz/pqr/client/settings}Con
 vertibleProperties
SHA-256-Digest: 5FszAtfpPXcLx/6FBWbfeg6E4fwFMRozV+Q+3rReATc= ...

Expected Output:

Manifest-Version: 1.0
Version-Info: ....

NetBeans-Simply-Convertible: {com/abc/xyz/pqr/client/settings}Con
 vertibleProperties

...

Answer 1

sed -e '
   4,$!d;      # skip non-relevant portion
   /Name:/N;   # grab the line coming after Name:
   /\n.* /d;   # what we were after is not this
   P;D
' yourfile

Answer 2

awk approach:

Let's say we have the following input file file.txt(considering that each line contains Line<number>: as first field):

Line1: a
Line2: b
Line3: c
Line4: Name: 123
Line5:  xyz
Line6: Name: 456
Line7:  abc
Line8: Name: 111
Line9: www
Line10: Num: 222
Line11:  abc
Line12: Name: 333
Line13:  ccc

---

awk '{ if ($2 == "Name:") { 
           if ((getline l) > 0){ 
               if (l ~ /^\S+  \S+/) { next } else { print $0 RS l }               
           }
       } else { print } 
}' file.txt

The output:

Line1: a
Line2: b
Line3: c
Line8: Name: 111
Line9: www
Line10: Num: 222
Line11:  abc

---

‘getline var’ - reads the next record from awk's input into the variable var

The getline command returns 1 if it finds a record and 0 if it encounters the end of the file.

Answer 3

You see that what you are asking is not clear: one answer deletes 4 lines (the two matching and the two subsequent ones); another deletes everything but the matching lines...

I'll throw in what I understand you want: I delete 2 lines, the one matching Name: 123 and the subsequent one. I do this with sed:

sed -e '/Name: 123/{N;d}' filename