Linux sha256sum command
The sha256sum command displays or checks SHA256 (256-bit) checksums. With no FILE, or when FILE is - (a dash), it reads the digest from standard input.
sha256sum [OPTION]... [FILE]...
|-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).|
There is no difference between binary and text mode option on GNU system.
The following four 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.|
|--strict||Exit non-zero for improperly formatted checksum lines.|
|-w, --warn||Warn about improperly formatted checksum lines.|
|--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.
Running the above command would give the SHA256 checksum of the example.iso file in the current directory. Below is an example of how the output may appear with the full SHA256 checksum followed by the file name.