Provided by: coreutils_8.21-1ubuntu5_amd64
sha256sum - compute and check SHA256 message digest
sha256sum [OPTION]... [FILE]...
Print or check SHA256 (256-bit) checksums. With no FILE, or when FILE is -, read standard input. -b, --binary read in binary mode -c, --check read SHA256 sums from the FILEs and check them --tag create a BSD-style checksum -t, --text read in text mode (default) The following three options are useful only when verifying checksums: --quiet don't print OK for each successfully verified file --status don't output anything, status code shows success -w, --warn warn about improperly formatted checksum lines --strict with --check, exit non-zero for any invalid input --help display this help and exit --version output version information and exit The sums are computed as described in FIPS-180-2. 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 input mode ('*' for binary, space for text), and name for each FILE.
Written by Ulrich Drepper, Scott Miller, and David Madore.
Report sha256sum bugs to firstname.lastname@example.org GNU coreutils home page: <http://www.gnu.org/software/coreutils/> General help using GNU software: <http://www.gnu.org/gethelp/> Report sha256sum translation bugs to <http://translationproject.org/team/>
Copyright © 2013 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>. This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.
The full documentation for sha256sum is maintained as a Texinfo manual. If the info and sha256sum programs are properly installed at your site, the command info coreutils 'sha256sum invocation' should give you access to the complete manual.