iredmail下安装脚本分析（一）---get_all.sh 文件所在目录为PKGS

check_user()
{
 # Check special user privilege to execute this script.
 if [ X"$(id -u)" != X"$(id -u ${1})" ]; then
  ECHO_ERROR "Please run this script as user: ${1}."
  exit 255
 else
  if [ X"$(id -u)" == X"0" ]; then
   export PATH="/usr/kerberos/sbin:/usr/kerberos/bin:/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"
  else
   :
  fi
 fi
}

check_hostname()
{
 echo ${HOSTNAME} | grep '\.' &>/dev/null
 [ X"$" != X"0" ] &&   ECHO_ERROR "Please configure a fully qualified domain name (FQDN) in /etc/hosts before we go further.\n\nExample:\n\n127.0.0.1 mail.iredmail.org mail localhost\n" &&   exit 255
}

check_runtime_dir() {
 [ -d ${RUNTIME_DIR} ] || mkdir -p ${RUNTIME_DIR}

 # Cleanup
 rm -f ${RUNTIME_DIR}/.pkg_install_failed &>/dev/null
}

if [ X"${DISTRO}" == X"RHEL" ]; then
 # Special package.
 # command: which.
 export BIN_WHICH='which'
 export PKG_WHICH='which'
 # command: wget.
 export BIN_WGET='wget'
 export PKG_WGET='wget'
elif [ X"${DISTRO}" == X"DEBIAN" -o X"${DISTRO}" == X"UBUNTU" ]; then
 if [ X"${OS_ARCH}" == X"x86_64" ]; then
  export pkg_arch='amd64'
 else
  export pkg_arch="${OS_ARCH}"
 fi
 # Special package.
 # command: which.
 export BIN_WHICH='which'
 export PKG_WHICH="debianutils"
 # command: wget.
 export BIN_WGET='wget'
 export PKG_WGET="wget"
 # command: dpkg-scanpackages.
 export BIN_CREATEREPO="dpkg-scanpackages"
 export PKG_CREATEREPO="dpkg-dev"
fi