I am trying to implement sha256 in a class in Objective C. In the process, I want to check the accuracy of what I am doing, by doing, what I **thought** was something simple....checking the value against the same operation in "terminal". But, I am stumped. The man pages for sha256 show this. and give an example thus. error I am getting is: I have tried every which way to Sunday ( including just about every variation of the above ) , but I cannot get this to work, and there is very little in "googlesphere" about this, so it's time to ask those that do know. Needless to say, my experience in terminal is somewhat limited, so any help would be greatly appreciated.