shasum

shasum [-a algorithm] [-b] [-c] [options] [files]

shasum is a unified Perl-based utility for computing and verifying SHA message digests across all algorithm variants. The -a option selects the algorithm: SHA-1 (default), SHA-224, SHA-256, SHA-384, SHA-512, and the truncated SHA-512/224 and SHA-512/256 variants. SHA-256 is the most commonly used for software distribution verification and security applications.In check mode (-c), shasum reads a file containing previously generated checksums and verifies each listed file against its recorded hash, reporting success or failure. Output format shows the hash followed by the filename, with BSD-style output (--tag) additionally including the algorithm name. Both formats are understood during verification.This command is the standard SHA utility on macOS and systems with Perl installed, providing equivalent functionality to the separate sha1sum, sha256sum, and sha512sum commands found in GNU coreutils.

-a ALG

Algorithm (1, 224, 256, 384, 512, 512224, 512256).

Binary mode.

Check hashes from file.

Text mode (default).

Read in Universal Newlines mode (produces same digest on Windows/Unix/Mac).

Read in BITS mode (ASCII '0' interpreted as 0-bit, '1' as 1-bit).

Status only, don't output anything (with -c).

Don't fail or report status for missing files (with -c).

Don't print OK for each successfully verified file (with -c).

Warn about improperly formatted checksum lines.

Exit non-zero for improperly formatted lines.

BSD-style output including algorithm name.

Show help.

SHA-1 is cryptographically weakened - use SHA-256+ for security. Hash verification requires original hash to be trusted.

shasum is a Perl script included with Perl. It provides a unified interface to SHA algorithms, mirroring the functionality of sha256sum and similar coreutils programs.

sha1sum(1), sha256sum(1), md5sum(1), openssl(1), b2sum(1)