Say you have the crc32 for a file, but you only have the data for the beginning (prefix) of the file. crc-trim-prefix will compute the crc32 for the missing suffix, which might help in locating it.
Usage: crc-trim-prefix prefix_file target_size target_crc
Example:
$ echo -n "Hello," > prefix.txt
$ echo -n " world!" > suffix.txt
$ cat prefix.txt suffix.txt > target.txt
$ wc -c target.txt
13 target.txt
$ crc32 target.txt
ebe6c6e6
$ crc-trim-prefix prefix.txt 13 ebe6c6e6
suffix len 7 crc 9297dfa9
$ crc32 suffix.txt
9297dfa9