SYD-SUM(1) General Commands Manual SYD-SUM(1)

syd-sum - Calculate checksum of the given file or standard input

syd-sum -a alg [-bhx] <file|->

Given a file, calculate the checksum of the file using the Linux Kernel Crypto API (AF_ALG).

Only regular files and FIFOs (pipes) may be hashed.

Given no positional arguments or "-" as argument, calculate checksum of standard input.

-a alg Hash algorithm to use (required).
Any algorithm listed in proc_crypto(5) with type ahash or shash may be used.
Use -a list to list available algorithms.
Examples: sha256, sha512, sha3-512, blake2b-256, md5, crc32c
-b Binary output.
-x Hexadecimal output (default).
-h Display help.

syd-sum -a sha256 /usr/bin/syd
echo hello | syd-sum -a blake2b-512
syd-sum -a crc32c -b /etc/passwd > /tmp/crc.bin

syd(1), syd(2), syd(5), syd-path(1), proc_crypto(5)

syd homepage: https://sydbox.exherbo.org/

Maintained by Ali Polatel. Up-to-date sources can be found at https://gitlab.exherbo.org/sydbox/sydbox.git and bugs/patches can be submitted to https://gitlab.exherbo.org/groups/sydbox/-/issues. Discuss in #sydbox on Libera Chat or in #sydbox:mailstation.de on Matrix.

2026-03-18