Adding XML element in XML file using sed command in shell script

Question

I am using sed command to insert an xml element into the existing xml file.

I have xml file as

Answer 1

You cannot have an unescaped newline in sed replacement text, that is $CONTENT in your example. sed uses the newline just like the shell does, to terminate a command.

If you need a newline in the replacement text, you need to precede it with a backslash.

There is another way to add text using the r option. For example:

Lets say your main file is;

$ cat file

    
        john
        123
    
    
        mike
        234
    

You text you want to add is in another file (not variable):

$ cat add.txt
    
        NewName
        NewID
    

You can do (using gnu sed):

$ sed '/<\/Students>/{ 
    r add.txt
    a \
    d 
}' file

    
        john
        123
    
    
        mike
        234
    
    
        NewName
        NewID
    

However, having given this option, it is still a very bad idea to parse xml with regular expression. It makes the solution very fragile and easy to break. Consider this as a learning exercise only.