sed Append command Insert line after first match
Example
Given a file file.txt with the following content:
line 1
line 2
line 3
You can add a new line after first matching line with the a command.
For portable use the a command must be followed immediately by an escaped newline, with the text-to-append on its own line or lines.
sed '
/line 2/a\
new line 2.2
' file.txt
GNU sed
Some versions of sed allow the text-to-append to be inline with the a command:
sed '/line 2/a new line 2.2' file.txt
The above commands will output:
line 1
line 2
new line 2.2
line 3
