Tag: sed

In this tutorial I will show a few useful examples of using “sed”.

-i: inline replace
-e: command to run

Add Line At End

Notice ($) and (a after $). Match last line (‘$’) and append (‘a’)

sudo sed -i -e "\$amy new line" /file/path/name.extension

Match Replace

This will replace the text on the left with the text on the right. Notice the “/” at the beginning and “/c\” in the middle.

sudo sed -i '/myCustomText=/c\myCustomText=newtext' /file/path/name.extension

Remove Matched Line

This will remove the line that matches the text. Notice the “/d” at the end and the “/” at the beginning.

sudo sed -i '/RemoveMyCustomText/d' /file/path/name.extension

Remove All Occurrences

This will remove all occurrences of “NIFI.APACHE.ORG” and replace with “REALM.CA”. Notice “/g” at end for global replace. Notice “s/” at the beginning. If means substitute. The “/” in the middle is used to denote the separation of the text to find and the text to replace.

sudo sed -i 's/NIFI.APACHE.ORG/REALM.CA/g' /file/path/name.extension

Handle ” Quotes / Handle XML / Add Tab

So the below example will go a few things. It will show you how to escape double quotes. It shows you how to add a tab and shows you how to handle xml. It also will add a line under text.

sudo sed -i -e "/<property name=\"Default Realm\">REALM.CA<\/property>/a \ \t<property name=\"Kerberos Config File\">/etc/krb5.conf<\/property>" /file/path/name.extension

Delete Lines By Number

sudo sed -i -e "$lineNumber,$maxLineNumber d" /file/path/name.extension