| Original author(s) | Ken Thompson |
|---|---|
| Developer(s) | AT&T Bell Laboratories |
| Initial release | November 3, 1971 |
| Operating system | Unix, Unix-like, Inferno |
| Platform | Cross-platform |
| Type | Command |
| License | coreutils: GPLv3+ |
sum is a legacy utility available on some Unix and Unix-like operating systems. This utility outputs a 16-bit checksum of each argument file, as well as the number of blocks they take on disk.[1] Two different checksum algorithms are in use. POSIX abandoned sum in favor of cksum.