usage: chunksum [-h] [-n ALG_NAME] [-f CHUNKSUMS_FILE] [-i INCR_FILE] [-m] [path ...] Print FastCDC rolling hash chunks and checksums. positional arguments: path path to compute chunksums optional arguments: -h, --help show this help message and exit -n ALG_NAME, --alg-name ALG_NAME chunksum algorithm name. -f CHUNKSUMS_FILE, --chunksums-file CHUNKSUMS_FILE chunksum file path, `-' for standard output. -i INCR_FILE, --incr-file INCR_FILE incremental updates file path -m, --multi-process same number of multi-processes as cpu alg-name: Format "fc[k|m|g][0-9][sha2|blake2b|blake2s][32]". For example, "fck4sha2", means using FastCDC("fc") with an average chunk size of 2**8=256KB("k8") and using sha256("sha2") to calculate the checksum. "fcm4blake2b32" means using FastCDC with an average chunk size of 2**4=16MB("m4") and using "blake2b" to calculate and output a checksum of length "32" bytes(save storage). For large files, you may using large chunk size, such as "m4", to reduce the number of chunks. (default: fck4sha2) chunksums-file and incr-file: You can specify the previous chunksums file if you want to resume a previous check, or if you want to find the incremental updates (new files) of the directory. Examples: $ chunksum /etc > ~/etc.chunksums $ chunksum -n fcm4blake2b32 -m ~/Videos $ chunksum -n fcm4blake2b32 -f ~/Videos/chunksums ~/Videos $ chunksum -n fcm4blake2b32 -f ~/chunksums -i ~/chunksums.incr ~/Videos