Hi,
Thanks for the info.

The problem got solved as follows.
the script was as follows
-------------------------------------------------------------
..
..
..
spout=`sqlplus -s $UP <<EOJ

SET HEAD OFF
SET AUTOTRACE OFF

WHENEVER SQLERROR EXIT 255

ALTER TRIGGER schema.trg DISABLE;

DECLARE

v_alter_statement VARCHAR2(255);

CURSOR c_constraint_name IS
SELECT constraint_name
FROM dba_constraints
WHERE table_name = 'XXXX';

BEGIN
FOR REC IN c_constraint_name
LOOP
v_alter_statement := 'ALTER TABLE XXXX';
v_alter_statement := v_alter_statement || ' ENABLE CONSTRAINT ';
v_alter_statement := v_alter_statement || REC.constraint_name;
DBMS_UTILITY.EXEC_DDL_STATEMENT(v_alter_statement);
END LOOP;


Exception

when OTHERS then
Rollback;
dbms_output.put_line ('Script failed : Sqlcode: ' || SQLCODE || ' Error message :' || SQLERRM);
return;

END;
/
EOJ`


ret_code=$?

echo "$spout" >>${logfile} 2>&1

if [ $ret_code -ne $SUCCESS ]
then
cat ${logfile}
exit $FATAL
fi
..
..
..


----------------------------------------------------------------

now what was happening was that if there is a pl/sql block in a script then whole of it is executed in one go (that's what a pl/sql block is supposed to mean , poor me didn't remember). now i had by mistake given an extra quote(') in the dbms_output.put_line of exception block. this raised an error. now if u give dbms_output.put_line b4 and after declare the one b4 declare gets printed but not the one after. so i was inferring that the control never reached inside the declare statement. whereas it did reach inside but the pl/sql block failed at the dbms_output.put_line in exception block!!!!

also i was getting directory listing of the directory in which i ran this script in the log file if the script failed. this was happening becaue i had the following statemnt

echo $spout >>${logfile} 2>&1

now the var spout had * in it since al the output of sql is directed into it and the procedure failed or in case some pl/sql error occured.

makin this statement as

echo "$spout" >>${logfile} 2>&1

made it fine.

Thanks n Regards
Manish