EDK2/OVMF update checker

#!/bin/sh -ex
if [ -z "${1}" ] ; then
    echo "Usage: ${0} biosAndStateLocation"
    echo "    Updates OVMF from jenkins to the biosAndStateLocation"
    echo "           biosAndStateLocation must be a directory, must exist and must be writeable"
    echo "           returns 4 if updated successfully, 0 if no updates available or some other error code on abject"
    echo "           or non-recoverable failure"
    echo "Usage: ${0} biosAndStateLocation"
    exit 1
fi
installLoc="${1}"
krax="https://www.kraxel.org/repos/jenkins/edk2"
currVer="$(cd "${installLoc}" && echo edk2.git-ovmf-x64*.rpm)"
kraxVer="$(curl "${krax}"/ 2> /dev/null | grep edk2.git-ovmf-x64 | sed -e 's/.*>edk2.git-ovmf-x64/edk2.git-ovmf-x64/' -e 's/rpm<.*/rpm/')"

if [ ! -z "${kraxVer}" ] && { [ "${currVer}" = "" ] || [ "${currVer}" != "${kraxVer}" ] ; } ; then
   tmpDir="$(mktemp -d)"
   curl -o "${installLoc}"/"${kraxVer}" "${krax}"/"${kraxVer}"
   7z x -o"${tmpDir}" "${installLoc}"/"${kraxVer}"
   7z x -o"${tmpDir}" "${tmpDir}"/"*.cpio"
   cp "${tmpDir}"/usr/share/edk2.git/ovmf-x64/OVMF_CODE-pure-efi.fd "${installLoc}"/OVMF_CODE-pure-efi.fd
   cp "${tmpDir}"/usr/share/edk2.git/ovmf-x64/OVMF_VARS-pure-efi.fd "${installLoc}"/OVMF_VARS-pure-efi.fd
   rm -rf "${tmpDir}"
   echo -n > "${installLoc}"/"${kraxVer}"
   if [ ! -z "${currVer}" ] ; then
       rm -f "${installLoc}"/"${currVer}"
   fi
   exit 4
else
   exit 0
fi
exit 1