open my $bash, "|-", "bash >/tmp/out.txt" or die $!;
print $bash <<EOL;
ls
df -h
uname -a
EOL

##</code><code>##

DOS:

OS Command - works OK:

open(OUTPUT, " > eol_dos.out") or die $!;
print OUTPUT <<`EOL`;
dir
EOL

exit 0;


sqlplus - this gives error : << was unexpected at this time.


$ENV{'ORACLE_SID'}="TEST";
$ENV{'ORACLE_HOME'}="C:\oracle\product\10.2.0";

open(OUTPUT, " > eol_sqlplus_dos.out") or die $!;
print OUTPUT <<`EOL`;
sqlplus -S "/as sysdba" <<"SQLEND"
set heading off
alter session set nls_date_format = 'DD-MON-YYYY HH24:MI:SS'
;

select 'Connected to the database on ' || sysdate
from dual
;
SQLEND
EOL

exit 0


UNIX:

OS Command - works OK:

open(OUTPUT, " > eol_unix.out") or die $!;
print OUTPUT <<`EOL`;
ls
echo
echo "+----------------------------------------------+"
echo
df
echo
echo "+----------------------------------------------+"
echo
uname -a
EOL

exit 0;


sqlplus - works OK:


$ENV{'ORACLE_SID'}="test";
$ENV{'ORACLE_HOME'}="/oracle/product/10.2.0";

open(OUTPUT, " > eol_sqlplus_unix_02.out") or die $!;
print OUTPUT <<`EOL`;
echo "Today is `date`"
echo
echo "+----------------------------------------------+"
echo
sqlplus -S "/as sysdba" <<"SQLEND"
set heading off
alter session set nls_date_format = 'DD-MON-YYYY HH24:MI:SS'
;

select 'Connected to the database on ' || sysdate
from dual
;
SQLEND
echo
echo "+----------------------------------------------+"
echo
EOL

exit 0