Programming :: Bash Md5sum Edit With Sed?

I am trying to get a checksum for a file in a subscripted variable in a bash script. md5sum outputs a checksum and the name of the input file. For example:

Code:
eval CSUM$K=$"(md5sum file)"

This might return something like this:

Code:
3cff5d5c0113959d0be62be34b97e05c file

I want to assign just the checksum to the variable in my shell script and omit the file name that follows. Is there something besides md5sum that will generate a checksum? Or if not, then I was thinking I might be able to extract the checksum without the file name using sed.