How can I append a variable text to last line of file via command line?
could you please tell me how I (a Linux-User) can add text to the last line of a text-file?

I have this so far:

    APPEND='Some/Path which is/variable'
    sed '${s/$/$APPEND/}' test.txt

It works, but $APPEND is added insted of the content of the variable. I know the reason for this is the singe quote (') I used for sed. 
But when I simply replace ' by ", no text gets added to the file.

Do you know a solution for this? I don't insist on using `sed`, it's only the first command line tool that came in my mind. You may use every standard command line program you like.

edit: I've just tried this:

    $ sed '${s/$/'"$APPEND/}" test.txt
    sed: -e Ausdruck #1, Zeichen 11: Unbekannte Option für `s'
How can I append a variable text to last line of file via command line?
===

could you please tell me how I (a Linux-User) can add text to the last line of a text-file?

I have this so far:

    APPEND='Some/Path which is/variable'
    sed '${s/$/$APPEND/}' test.txt

It works, but $APPEND is added insted of the content of the variable. I know the reason for this is the singe quote (') I used for sed. 
But when I simply replace ' by ", no text gets added to the file.

Do you know a solution for this? I don't insist on using `sed`, it's only the first command line tool that came in my mind. You may use every standard command line program you like.

edit: I've just tried this:

    $ sed '${s/$/'"$APPEND/}" test.txt
    sed: -e Ausdruck #1, Zeichen 11: Unbekannte Option für `s'