How to concatenate stdin and a string?

Question

How to I concatenate stdin to a string, like this?

echo \"input\" | COMMAND \"string\"

and get

inputstring

Answer 1

I'm often using pipes, so this tends to be an easy way to prefix and suffix stdin:

echo -n "my standard in" | cat <(echo -n "prefix... ") - <(echo " ...suffix")
prefix... my standard in ...suffix