jb@217desktop:~/Downloads$ sha256sum trisquel-netinst_9.0.1_amd64.iso

dc2394eaa2601227b04fad72975c3f7fc974ca27cbd83e70ac5680aced756232  trisquel-netinst_9.0.1_amd64.iso

jb@217desktop:~/Downloads$ cat trisquel-netinst_9.0.1_amd64.iso.sha256
dc2394eaa2601227b04fad72975c3f7fc974ca27cbd83e70ac5680aced756232  trisquel-netinst_9.0.1_amd64.iso

jb@217desktop:~/Downloads$ echo sfkjgsdbnfgvk > test.txt
jb@217desktop:~/Downloads$ cat test.txt
sfkjgsdbnfgvk

jb@217desktop:~/Downloads$ sha256sum test.txt
851099aabd9ca5cfb4b029c6ee6c8692671527813a65b3f14d762b93dfd632d4  test.txt

jb@217desktop:~/Downloads$ echo sfkjgsdbnfgvk | sha256sum
851099aabd9ca5cfb4b029c6ee6c8692671527813a65b3f14d762b93dfd632d4  -