tail output of program

Question

How do you use tail to get the last line outputted by a program. I've tried the following so far:

echo `cmd` >> stdin && tail -1 stdin

For instance:

henry@henry-pc:~$ echo "abc\n123" >> stdin && tail -1 stdin
abc\n123

Solution

You do not have to specify stdout as the output as it is natural. You would want to use a pipe char to pipe the output (stdout) to the tail utility.

You would want do to something like:

printf 'abc\n123\n' | tail -1

This will print 123.