Append text to file from command line without using io redirection

Question

If you don’t mind using sed then,

$ cat test 
this is line 1
$ sed -i '$ a\this is line 2 without redirection' test 
$ cat test 
this is line 1
this is line 2 without redirection

As the documentation may be a bit long to go through, some explanations :

-i means an inplace transformation, so all changes will occur in the file you specify
$ is used to specify the last line
a means append a line after
\ is simply used as a delimiter