shasum - Print or Check SHA Checksums
- 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
- -p, --portable read files in portable mode
- produces same digest on Windows/Unix/Mac
- -t, --text read in text mode (default)
- The following two options are useful only when verifying checksums:
- -s, --status don't output anything, status code shows success
- -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-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, `?' for portable), and name for each FILE.
- 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 easy it is 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.
Copyright (c) 2003-2011 Mark Shelor <firstname.lastname@example.org>.