# Pastebin BpumQpEw
#!/bin/bash
...

# Determine platform & init vars
cumulative_RC=0
OS=$(uname)
if [[ $OS =~ Darwin ]]; then # MacOS(X)
    systemctl="launchctl"
    sudo="sudo"
    ln="ln -nfs"
    gsed="gsed" # installed via (home)brew
    shellcheck_dir="utilities/shellcheck/macos/"
elif [[ $OS =~ CYGWIN ]]; then
    systemctl="sc.exe"
    sudo=""
    ln="winln -fs"
    gsed="sed"
    shellcheck_dir="utilities/shellcheck/windows/"
elif [[ $OS =~ Linux ]]; then
    systemctl="sytemctl"
    sudo="sudo"
    ln="ln -nfs"
    gsed="sed"
    shellcheck_dir="utilities/shellcheck/linux/"
else
    echo 'x Error, unknown platform "'$OS'", only MacOS (Darwin), Windows (via CYGWIN), and Linux currently supported!'
    exit 2
fi;
files_to_check=$(git status --porcelain | egrep '^M.*' | egrep '\.*sh$' | awk '{ print $2}')
for i in "${files_to_check[@]}"; do
    "${shellcheck_dir}"/shellcheck -S error "${i}"
    cumulative_RC=$((RC+$?))
done;
if [[ "${cumulative_RC}" -ne 0 ]]; then
    echo 'x Error, one or more files failed shellcheck!  See output above.  Failing commit with cumulative_RC = '${cumulative_RC}
    exit "${cumulative_RC}"
fi;