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

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

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.

Using ed:

$ printf '%s\n' 'g/^ / s///\' '-,.j' 'g/^Name: /d' 'g/SHA-256-Digest: /d' '4,$g/^$/d' ,p Q | ed -s file
Manifest-Version: 1.0
Version-Info: ....

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

This applies the following edit script to you input file:

g/^ / s///\
-,.j
g/^Name: /d
g/SHA-256-Digest: /d
4,$g/^$/d
,p
Q

This consists of six separate commands:

1. The two commands s/// and -,. j applied to every line that starts with a space character. The empty regular expression in the s command re-uses the expression ^ from the preceding g command (which is used for applying one or more commands to lines matching a regular expression), so the s command removes the first empty space on lines that start with empty spaces. The j command then joins the modified line with the previous line. This effectively undoes the wrapping of the lines in the input data.

2. The command d is applied to all lines that start with Name: , removing these.

3. Similarly, lines starting with SHA-256-Digest: are removed.

4. Empty lines are removed from line 4 onwards.

5. We output the complete buffer to standard output to display the result.

6. Q quits the editor unconditionally (you could use wq to write the changes back to the original file).

Rather than post-processing the file multiple times, you can use something like awk to handle it all in one go. This variant removes the Name and SHA-256-Digest blocks - plus of course their continuation lines, if any.

awk '
    /^$|^[^ ]/ {skip=0}                   # Stop skipping once we hit a blank line or non-space
    /^(Name|SHA-256-Digest):/ {skip=1}    # Start skipping matching headers
    !skip                                 # Output the line unless we are skipping it
' MANIFEST.MF

Output from your example

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




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

It wouldn't be wildly hard to reduce the multiple blank lines to singletons, but as your example output didn't do that I haven't do so either.

You can squash this into one line if you must, but it's not nearly as readable:

awk '/^$|^[^ ]/{skip=0} /^(Name|SHA-256-Digest):/{skip=1} !skip' MANIFEST.MF

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