Search for string in filename, not file content

Shell Programming and Scripting
1

How can I search for a string in a filename? For example, I want to know if a filename (not the file contents) contains the string "test".

2 
for i in *
do
   echo "$i" | grep -q 'test'  && echo "$i has the word test in it"
done

basically echo the filename thru a pipe to grep.

3

In what language?

Assuming bourne shell, how about:

expr index filename len >/dev/null && echo ok

js.

4

Just 1 file name? Is this sufficient?

$> echo somefilename| awk '/test/ {print "yo"}'
$> echo sometestfilename| awk '/test/ {print "yo"}'
yo