如何在Perl中打开外部命令（sqlplus）并连续使用它而无需重新启动

Question

I am beginner in Perl script. and am writing perl script which opens external command ( sqlplus ). I want to open sqlplus with prelim setting, and get session information periodically. That is, After opening sqlplus with (oradebug setmypid) and (oradebug direct_access set mode=unsafe),then I want to send retrieval query(oradebug direct_access select * from x\\$ksuse\\n) continuously without restart sqlplus.

Following code might make you understand my question better

my $set = "oradebug setmypid;\n oradebug direct_access set mode=unsafe;\n oradebug direct_access select * from x\$ksuse\n";
open(PIPE, '|-', "/opt/oracle/product/11.2.0/db_1/bin/sqlplus -prelim system/oracle as sysdba");

print PIPE $set;    #if I call this call continuously, it means I open sqlplus again, again...This is not what I want^^

Is there any way of running retrieval query continuously after opening sqlplus once?

Thank you in advance

Answer 1

Generally speaking Expect is rather capable. There are lots of intricacies to handle when interfacing with an interactive shell command and Expect handles many of them for you.

However I must ask are you certain this (interfacing with sqlplus from perl) is the best approach? I'm not nearly enough of an Oracle expert to understand what your code is wanting to achieve, but have you tried sqlplus start syntax

in query.sql :

oradebug setmypid;
oradebug direct_access set mode=unsafe;
oradebug direct_access select * from x$ksuse;
exit;

in shell:

/opt/oracle/product/11.2.0/db_1/bin/sqlplus -prelim system/oracle as sysdba @query >data.txt

This should put data.txt in the current working directory with your results.

Also, perl DBI is rather capable too, although I must say I don't understand what your code is trying to do so I don't know if DBI is able to help you with that. Google is your friend here.

Hope this helps!