The following command will produce a hash of 256-bits of the Hello messages using the SHA-256 algorithm:
$ echo -n 'Hello' | openssl dgst -sha256 (stdin)= 185f8db32271fe25f561a6fc938b2e264306ec304eda518007d1764826381969
Note that even a small change in the text, such as changing the case of the letter H, results in a big change in the output hash. This is known as the avalanche effect, as discussed earlier:
$ echo -n 'hello' | openssl dgst -sha256 (stdin)= 2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824
Note that both outputs are completely different:
Hello: 18:5f:8d:b3:22:71:fe:25:f5:61:a6:fc:93:8b:2e:26:43:06:ec:30:4e:da:51:80:07: d1:76:48:26:38:19:69
hello: 2c:f2:4d:ba:5f:b0:a3:0e:26:e8:3b:2a:c5:b9:e2:9e:1b:16:1e:5c:1f:a7:42:5e:73: ...
