Remove Duplicate Line in Vim?

Question

I\'m trying to use VIM to remove a duplicate line in an XML file I created. (I can\'t recreate the file because the ID numbers will change.)

The file looks something

Answer 1

It seems like the bash, python and perl methods would work but you are already in vim. So why not create a function like:

function! RemoveDuplicateLines()
    let lines={}
    let result=[]
    for lineno in range(line('$'))
        let line=getline(lineno+1)
        if (!has_key(lines, line))
            let lines[line] = 1
            let result += [ line ]
        endif
    endfor
    %d
    call append(0, result)
    d
endfunction