No sha256sum in MacOS

The CoreUtils package is also published as a Brew formulae. So if you have Brew installed you can also just run:

brew install coreutils

Then add PATH="/usr/local/opt/coreutils/libexec/gnubin:$PATH" to ~/.bashrc, run source ~/.bashrc and you're done.

After investigating a little, I found a ticket in an unrelated software in GitHub sha256sum command is missing in MacOSX , with several solutions:

• installing coreutils

  sudo port install coreutils
  

  It installs sha256sum at /opt/local/libexec/gnubin/sha256sum

• As another possible solution, using openssl:

function sha256sum() { openssl sha256 "$@" | awk '{print $2}'; }

• As yet another one, using the shasumcommand native to MacOS:

function sha256sum() { shasum -a 256 "$@" ; } && export -f sha256sum

Supplemental Answer to Mig82's, whose answer handles the g-prefix for all executables in coreutils. I offer a tightly-scoped solution.

After coreutils installing with

brew install coreutils

Results in ls /usr/local/bin/gsha* will list the g-prefixed executables:

• /usr/local/bin/gsha1sum
• /usr/local/bin/gsha224sum
• /usr/local/bin/gsha256sum
• /usr/local/bin/gsha384sum
• /usr/local/bin/gsha512sum

The solution is to create a symbolic link to the ones you want using a non-prefixed name (or take a risk in breaking some programs that rely on BSD executables and use the no g prefix Homebrew option)

Example

shaarray=(\
/usr/local/bin/gsha1sum
/usr/local/bin/gsha224sum
/usr/local/bin/gsha256sum
/usr/local/bin/gsha384sum
/usr/local/bin/gsha512sum
)
function installsha() {
  for i in "${shaarray[@]}"
  do
    printf "$i\n" | perl -pe 'printf $_; s/gsha/sha/' | xargs -n 2 ln -s
  done
}