md5

#!/usr/bin/env bash

variable_is_nonempty()
{
  typeset _variable
  _variable="${1:-}"

  if [[ -n "${_variable}" ]]
  then
    eval "[[ -n \"\${${_variable}:-}\" ]]" || return $?
  else
    fail "Cannot check if variable is nonempty; no variable was given."
  fi

}

command_exists()
{
  typeset _name
  _name="${1:-}"

  if variable_is_nonempty _name
  then
    builtin command -v "${_name}" > /dev/null 2>&1 || return 1
  else
    fail "Cannot test if command exists; no command name was given."
  fi
}

if (( ${rvm_trace_flag:=0} == 2 ))
then
  set -x
  export rvm_trace_flag
fi

_archive="${1}"
shift || fail "archive name not given in first param"

md5="${1}"
shift || fail "md5 value not given in second param"

# Swiped from BDSM
if command_exists md5
then
  archive_md5=$(md5 -q "${_archive}")
elif command_exists md5sum
then
  archive_md5="$(md5sum "${_archive}")"
  archive_md5="${archive_md5%% *}"
else
  for _path in /usr/gnu/bin /sbin /bin /usr/bin /usr/sbin
  do
    if [[ -x "${_path}/md5" ]]
    then
      archive_md5=$(${_path}/md5 -q "${_archive}")
    elif [[ -x "${_path}/md5sum" ]]
    then
      archive_md5="$(${_path}/md5sum "${_archive}")"
      archive_md5="${archive_md5%% *}"
    fi
  done
fi

[[ "${archive_md5}" == "${md5}" ]] || exit $?