mosesdecoder/jam-files/check-environment.jam

# get stuff from environment variables if not set on the command line
# unless blocked explicitly
for local what in cmph irstlm  
{  
   if ! [ option.get "with-$(what)" ] && ! [ option.get "no-$(what)" : : no ] 
   {
      local where = [ os.environ "$(what:U)_ROOT" ] ;
      if $(where) 
      { 
         echo "setting option with-$(what) from environment variable "
              "$(what:U)_ROOT ." ;
         option.set "with-$(what)" : $(where) ; 
       }
   }
   local where = [ option.get "with-$(what)" ] ;
}

# if --with-moses-regtest is specified without a directory
local regtest = [ option.get "with-moses-regtest" : no : yes ] ;
if $(regtest) = yes 
{ # regtests requested but no path given 
  echo "Regression tests requested but no path given." ; 
  local $(where)  = [ os.environ "MOSES_REGTEST_ROOT" ] ;
  if ! $(where) 
  {
    local HOME = [ os.environ "HOME" ] ; 
    if [ path.exists $(HOME)/moses-regression-tests ] 
    {
      echo "Using ~/moses-regression-tests as the default." ; 
      option.set "with-moses-regtest" : "~/moses-regression-tests" ; 
    }
  }
  else 
  { 
    if [ path.exists $(where) ] 
    {
      echo "Using $(where) from environment variable MOSES_REGTEST_ROOT."
      option.set "with-regtest" : $(where) ; 
    }
  }
}