The CRC32 application was designed to be a small command line tool for calculating 32-bit CRCs.
You can use CRC to figure out if two files are identical or not without actually having both files present. If the 32-bit values generated by this program match, you can be relatively certain that the files are idential. CRC runs from the command line, but doesn't accept long filenames.
NOTE: The CRC's generated will not match those found in ZIP archives (a different CRC polynomial is being used). You should only expect CRC values to be equal when using this program on both files in question.