- Calculate the SHA1 checksum for a file:
- Calculate the SHA256 checksum for a file:
shasum --algorithm 256 filename
- Calculate the SHA512 checksum for multiple files:
shasum --algorithm 512 filename1 filename2
- Calculate and save the list of SHA256 checksums to a file:
shasum --algorithm 256 filename1 filename2 > filename.sha256
- Check a file with a list of sums against the directory's files:
shasum --check list_file
- Check a list of sums and only show a message for files for which verification fails:
shasum --check --quiet list_file
- Calculate the SHA1 checksum from stdin:
somecommand | shasum
Usage: shasum [OPTION]... [FILE]... Print or check SHA checksums. With no FILE, or when FILE is -, read standard input. -a, --algorithm 1 (default), 224, 256, 384, 512, 512224, 512256 -b, --binary read in binary mode -c, --check read SHA sums from the FILEs and check them --tag create a BSD-style checksum -t, --text read in text mode (default) -U, --UNIVERSAL read in Universal Newlines mode produces same digest on Windows/Unix/Mac -0, --01 read in BITS mode ASCII '0' interpreted as 0-bit, ASCII '1' interpreted as 1-bit, all other characters ignored The following five options are useful only when verifying checksums: --ignore-missing don't fail or report status for missing files -q, --quiet don't print OK for each successfully verified file -s, --status don't output anything, status code shows success --strict exit non-zero for improperly formatted checksum lines -w, --warn warn about improperly formatted checksum lines -h, --help display this help and exit -v, --version output version information and exit When verifying SHA-512/224 or SHA-512/256 checksums, indicate the algorithm explicitly using the -a option, e.g. shasum -a 512224 -c checksumfile The sums are computed as described in FIPS PUB 180-4. When checking, the input should be a former output of this program. The default mode is to print a line with checksum, a character indicating type (`*' for binary, ` ' for text, `U' for UNIVERSAL, `^' for BITS), and name for each FILE. The line starts with a `\' character if the FILE name contains either newlines or backslashes, which are then replaced by the two-character sequences `\n' and `\\' respectively. Report shasum bugs to email@example.com
Running shasum is often the quickest way to compute SHA message digests. The user simply feeds data to the script through files or standard input, and then collects the results from standard output.
The following command shows how to compute digests for typical inputs such as the NIST test vector “abc”:
perl -e "print qq(abc)" | shasum
Or, if you want to use SHA-256 instead of the default SHA-1, simply say:
perl -e "print qq(abc)" | shasum -a 256
Since shasum mimics the behavior of the combined GNU sha1sum, sha224sum, sha256sum, sha384sum, and sha512sum programs, you can install this script as a convenient drop-in replacement.
Unlike the GNU programs, shasum encompasses the full SHA standard by allowing partial-byte inputs. This is accomplished through the BITS option (-0). The following example computes the SHA-224 digest of the 7-bit message 0001100:
perl -e "print qq(0001100)" | shasum -0 -a 224
Copyright (C) 2003-2018 Mark Shelor <firstname.lastname@example.org>.
shasum is implemented using the Perl module Digest::SHA.