crc32 [-fFvV] AREA
Calculate a CRC32 checksum of a memory area.
| -f FILE | Use file instead of memory. |
| -F FILE | Use file to compare. |
| -v CRC | Verify |
| -V FILE | Verify with CRC read from FILE |
| -r <var> | Set <var> to the checksum result |
| -s <var> | Set <var> to the data size |