Re: TNSPING for the instant client

From: Mladen Gogala <mgogala_at_yahoo.com>
Date: Fri, 15 May 2015 11:09:18 -0400
Message-ID: <55560C1E.5010700_at_yahoo.com>

Thank you Jeff!
I will still finish my Perl script this weekend. It's not a big deal. Regards,

On 05/15/2015 08:57 AM, Jeff Smith wrote:
>
> For what it’s worth, we’ve added a TNSPING command to SQLcl, which is
> still in Early Adopter mode.
>
> *From:*Mark W. Farnham [mailto:mwf_at_rsiz.com]
> *Sent:* Friday, May 15, 2015 6:31 AM
> *To:* niall.litchfield_at_gmail.com
> *Cc:* Oracle L
> *Subject:* RE: TNSPING for the instant client
>
> Interesting idea to use sqlplus with flags when there is no tnsping to
> be found.
>
> *From:*oracle-l-bounce_at_freelists.org
> <mailto:oracle-l-bounce_at_freelists.org>
> [mailto:oracle-l-bounce_at_freelists.org] *On Behalf Of *Niall Litchfield
> *Sent:* Friday, May 15, 2015 6:20 AM
> *Cc:* Oracle L
> *Subject:* Re: TNSPING for the instant client
>
> I rather think I prefer Laurent's approach
> http://laurentschneider.com/wordpress/2012/11/tnsping-and-instant-client.html.
> I don't agree that tnsping is the equivalent of seeing if a given port
> on a given hostname/dns alias is accessible.
>
> The line
>
> ·Parses the TNS entry and extracts the host and port information
>
> Rather assumes a tnsnames.ora file it seems to me, at the very least
> an indistinguishable tool would need to deal with ldap names etc.
>
> On Thu, May 14, 2015 at 6:39 AM, Mladen Gogala
> <dmarc-noreply_at_freelists.org <mailto:dmarc-noreply_at_freelists.org>> wrote:
>
> Instant client is an excellent thing. It not only enables me to link
> PHP oci8 interface and Perl DBD::Oracle, it gives me the full-fledged
> sqlplus. There is only one utility that I am sorely missing: tnsping.
> I know that everybody knows that, but here is what tnsping does:
>
> * Parses the TNS entry and extracts the host and port information
> * Contacts the host on the specified port and checks whether there
> is a listener listening on that port.
>
> Sometimes, installing the full client is not an option, like on my
> Ubuntu box:
>
> mgogala_at_umajor:~$ cat /etc/lsb-release
> DISTRIB_ID=Ubuntu
> DISTRIB_RELEASE=15.04
> DISTRIB_CODENAME=vivid
> DISTRIB_DESCRIPTION="Ubuntu 15.04"
>
> For some reason, Oracle Corp. doesn't support Ubuntu for the full
> client, so its installation is not an option. I really like tnsping,
> so here is what I came up with:
>
> #!/bin/sh
> export PORT=1521
> if [ -z "$1" ]; then
> echo "USAGE:tnsping hostname <port>"
> echo " Port defaults to 1521";
> exit 1;
> fi;
> [ ! -z "$2" ] && export PORT=$2;
> nc -v -z -w 3 $1 $PORT
>
> This is not a complete equivalent of the original "tnsping" utility,
> because it doesn't parse the name and tell me where the sqlnet.ora is,
> but it does ask the desired host whether there is a listener on the
> desired port. The result looks like this:
>
> mgogala_at_umajor:~$ tnsping oradb
> Connection to oradb 1521 port [tcp/*] succeeded!
> mgogala_at_umajor:~$ tnsping oradb 1526
> nc: connect to oradb port 1526 (tcp) failed: Connection refused
> mgogala_at_umajor:~$ tnsping oradb 22
> Connection to oradb 22 port [tcp/ssh] succeeded!
>
> I will probably modify the script and check whether TNS_ADMIN is
> defined and whether $TNS_ADMIN/sqlnet.ora exists, but so far, this
> script does what I wrote it for: it checks whether there is a listener
> on the host. Note that it even did "tnsping" on the port 22 (ssh),
> which is not possible with the original tnsping. So, for all instant
> client users and other Oracle enthusiasts, you are hereby granted the
> right to use and modify this script according to your needs, without
> any restrictions. Also, there is no warranty of any kind, either
> explicit or implied.
> The script depends on the "netcat" or "nc" command which does all of
> the dirty work. This short script is just a wrapper and I hope that
> some among you may find it useful. I will probably rewrite it in Perl
> and parse the TNS entry, but that's far too much work for this late
> hour. There is Net::Netcat module on CPAN, which makes it possible to
> write an even better emulation which will be literally
> indistinguishable from the original.
> Enjoy.
>
>
> --
> Mladen Gogala
> Oracle DBA
> http://mgogala.freehostia.com
>
>
>
> --
>
> Niall Litchfield
> Oracle DBA
> http://www.orawin.info
>

-- 
Mladen Gogala
Oracle DBA
http://mgogala.freehostia.com


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Received on Fri May 15 2015 - 17:09:18 CEST