sha1sum: Print or check SHA-1 digests ¶sha1sum computes a 160-bit checksum for each specified file.
The SHA-1 digest is more reliable than a simple CRC (provided by
the cksum command) for detecting accidental file corruption,
as the chances of accidentally having two files with identical SHA-1
are vanishingly small. However, it should not be considered secure
against malicious tampering: although finding a file with a given SHA-1
fingerprint is considered infeasible at the moment, it is known how
to modify certain files, including digital certificates, so that they
appear valid when signed with an SHA-1 digest. For more secure hashes,
consider using ‘sha2’, ‘sha3’, or ‘blake2b’,
available through the cksum --algorithm option.
See cksum: Print and verify file checksums.
If a file is specified as ‘-’ or if no files are given
sha1sum computes the checksum for the standard input.
sha1sum can also determine whether a file and checksum are
consistent. Synopsis:
sha1sum [option]... [file]...
sha1sum uses the ‘Untagged output format’
for each specified file, as described at cksum output modes.
The program accepts cksum common options. Also see Common options.