BH-AltSysRq/hasher-cli ? reverse-engineered prompt

Build me a small command line tool in C that takes a file path and prints the file’s SHA 256 hash using OpenSSL’s EVP API.

I want it to be simple to compile with a Makefile, and easy to run like ./hasher-cli myfile.png. If the file is missing or can’t be read, show a clear error message instead of crashing. If no filename is given, print a short usage hint.

Please keep it lightweight and focused on hashing one file at a time, and make sure the output is just the hash in a clean format. If you need to check anything about the current OpenSSL docs while implementing it, go ahead and look them up online.