CODEWITHSUNDEEP
bashunixawksedgrep
asfas
asfas

Reputation: 31

Look for a substring in a file and comment that line and insert new line underneath the commented line

I'm trying to look for a substring --port 1234 in a file and if the line is not commented then, comment out the line with # and insert a new line underneath it defined as this is the new path: /new/path/to/file. If the line containing --port 1234 is already commented, then do nothing. If substring --port 1234 is not found in the file then echo "not found"

Sample input:

somecode somecode
somecode somecode --port 1234 somecode somecode somecode
somecode somecode

Sample output:

somecode somecode
#somecode somecode --port 1234 somecode somecode somecode
This is the new path: /new/path/to/file
somecode somecode

Here's what I have so far:

sed -E '/--port 1234/!b;/^[^#]/!b;

so far I've only figured out how to ignore if the line is already commented, or if a line does not contain --port 1234. Very new to bash script!

Upvotes: 2

Views: 57

Answers (2)

markp-fuso
markp-fuso

Reputation: 35146

Sticking with the sed idea:

Sample input, with and without leading comment (#):

$ cat myfile
somecode somecode
somecode somecode --port 1234 somecode somecode somecode
somecode somecode
#somecode somecode --port 1234 somecode somecode somecode
somecode somecode

One sed idea:

$ sed -E 's|^([^#].*--port 1234.*)$|#\1\nThis the new path: /new/path/to/file|' myfile
somecode somecode
#somecode somecode --port 1234 somecode somecode somecode
This the new path: /new/path/to/file
somecode somecode
#somecode somecode --port 1234 somecode somecode somecode
somecode somecode

Once OP is satisfied with the result the -i flag can be added to perform an inplace update of the file.

Upvotes: 0

anubhava
anubhava

Reputation: 785721

awk is more suitable for this job.

Sample File:

cat file

foo bar
#somecode somecode --port 1234 somecode somecode somecode
somecode somecode
somecode somecode --port 1234 somecode somecode somecode
somecode somecode

Use gnu awk as:

awk -i inplace '/--port 1234 / && !/^#/ {
   print "#" $0 ORS "This is the new path: /new/path/to/file"
   next
} 1' file

foo bar
#somecode somecode --port 1234 somecode somecode somecode
somecode somecode
#somecode somecode --port 1234 somecode somecode somecode
This is the new path: /new/path/to/file
somecode somecode

Upvotes: 1

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