oraenv oddities in 11gR2

Recently I was installing a regular 11gR2 installation and tried to use it by an other user than the software owner or a member of the dba group. A - so called - regular user.

When I ran oraenv to configure my environment for the ORACLE_SID I was going to use I was told that

ORACLE_BASE environment variable is not being set since this
information is not available for the current user ID ciber
You can set ORACLE_BASE manually if it is required.

This made me wonder why so I dived in the /usr/local/bin/oraenv script and found:

ORABASE_EXEC=$ORACLE_HOME/bin/orabase

if [ ${ORACLE_BASE:-"x"} != "x" ]; then
   echo "The Oracle base for ORACLE_HOME=$ORACLE_HOME is $ORACLE_BASE"
else
   if [ -w $ORACLE_HOME/inventory/ContentsXML/oraclehomeproperties.xml ]; then
     if [ -e $ORABASE_EXEC ] ; then
        if [ -x $ORABASE_EXEC ]; then
           ORACLE_BASE=`$ORABASE_EXEC`
           export ORACLE_BASE
           echo "The Oracle base for ORACLE_HOME=$ORACLE_HOME is $ORACLE_BASE"
        else
           echo "The $ORACLE_HOME/bin/orabase binary does not have execute privilege"
           echo "for the current user, $USER.  Rerun the script after changing"
           echo "the permission of the mentioned executable."
        fi
     else
        ORACLE_BASE=$ORACLE_HOME
        export ORACLE_BASE
        echo "The Oracle base for ORACLE_HOME=$ORACLE_HOME is $ORACLE_BASE"
     fi
   else
     echo "ORACLE_BASE environment variable is not being set since this"
     echo "information is not available for the current user ID $USER."
     echo "You can set ORACLE_BASE manually if it is required."
   fi
fi

What this code does is
1) check ORACLE_BASE
2) if set => all ok and report ORACLE_BASE
3) else, check if $ORACLE_HOME/inventory/ContentsXML/oraclehomeproperties.xml is WRITEABLE and try to set ORACLE_BASE using $ORACLE_HOME/bin/orabase.

I made a little tweek on this script, to check for READABLE on $ORACLE_HOME/inventory/ContentsXML/oraclehomeproperties.xml. Why would we give an ordinary user write privileges on anything within ORACLE_HOME? ([in]Secure by default?).

Still I keep getting this error:

ORACLE_BASE environment variable is not being set since this
information is not available for the current user ID ciber.
You can set ORACLE_BASE manually if it is required.

So when the script is no longer the culprit, the filesystem security bits have to be it. In unix, to be able to access a file, all directories that we have to pass through need to have at least execute permission for me to pass. The fresh created app directory (/home/oracle/app) has 770 so I won't be able to pass this one.

chmod o+x app

to fix that but still I am getting the same error. When digging deeper I get to $ORACLE_HOME/inventory that also has 770 defined on it. Here again:

chmod o+x $ORACLE_HOME/inventory

Now it is the ContentsXML directory that is blocking me, it again has 770.

chmod o+x $ORACLE_HOME/inventory/ContentsXML

Finally we get to the oraclehomeproperties.xml file, this has 660 for the permisssion bits. To fix this

chmod o+r $ORACLE_HOME/inventory/ContentsXML/oraclehomeproperties.xml

Finally oraenv does no longer complain.

If it is important enough to give an error message when running oraenv, why make this file inaccessible to other users? BTW: my previous post was more or less caused by figuring out this setup. I thought I made an error so I wanted to re-install the ORACLE_HOME, just to make sure that what I write is right.