PL/TCL bug (?)

Wow!

What are the odds...

I had just created a C function which would allow
the database to determine wether or not a file exists
somewhere on the filesystem (readable by user
postgres, of course) and return 0 if not and
1 if the file exists. I then used the function in
a VIEW and used a MS Access front-end to make
pretty reports from the view, and I arrived at the
exact same symbol missing from the dynamic linker,
since I used stat() to test for the existence of the
file. I wound up using fopen() (a poor alternative)
in the custom function, because the backend didn't
have any linker problems with it. I spent hours
working under the assumption that I was using the
wrong compiler flags with gcc and ld, and finally
gave up trying to use stat(). Note that this could
still be the case...

I have the EXACT same configuration as you:

Intel
Linux RedHat 5.2
Kernel 2.0.36
PostgreSQL 6.4

Interesting....

---Daniele Orlandi <daniele@orlandi.com> wrote:

Hi,

I'm having serious problems with postgresql and TCL as a procedural

language.

I did a clean compilantion and install --with-tcl.
I did an initdb, created the language and a demo function found on

the site.

This is the result:

a=> create function pltcl_call_handler() returns opaque
a-> as '/usr/postgres/lib/pltcl.so'
a-> language 'C';
CREATE
a=>
a=> create trusted procedural language 'pltcl'
a-> handler pltcl_call_handler
a-> lancompiler 'PL/Tcl';
CREATE
a=> CREATE FUNCTION tcl_max (int4, int4) RETURNS int4 AS '
a'> if {$1 > $2} {return $1}
a'> return $2
a'> ' LANGUAGE 'pltcl';
CREATE
a=> select tcl_max(3,7);
ERROR: Load of file /usr/postgres/lib/pltcl.so failed:

/usr/lib/libtcl8.0.so:

undefined symbol: stat

a=> select tcl_max(3,7);
pqReadData() -- backend closed the channel unexpectedly.
This probably means the backend terminated abnormally before

or while

processing the request.
We have lost the connection to the backend, so further processing is
impossible. Terminating.
----------

The same happens on two other 6.4.0 - 6.4.2 installations. All

machines are

Intel based RedHat 5.2 Linuxes with kernel 2.0.36, tcl-8.0.3.
I wasn't able to test this with the current snapshot because I

hadn't been able

to initdb.

Any guess ?

Bye!

--
Daniele

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

Daniele Orlandi - Utility Line Italia - http://www.orlandi.com
Via Mezzera 29/A - 20030 - Seveso (MI) - Italy

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

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Daniele Orlandi wrote:

Hi,

I'm having serious problems with postgresql and TCL as a procedural language.

I did a clean compilantion and install --with-tcl.
I did an initdb, created the language and a demo function found on the site.

This is the result:

a=> create function pltcl_call_handler() returns opaque
a-> as '/usr/postgres/lib/pltcl.so'
a-> language 'C';
CREATE
a=>
a=> create trusted procedural language 'pltcl'
a-> handler pltcl_call_handler
a-> lancompiler 'PL/Tcl';
CREATE
a=> CREATE FUNCTION tcl_max (int4, int4) RETURNS int4 AS '
a'> if {$1 > $2} {return $1}
a'> return $2
a'> ' LANGUAGE 'pltcl';
CREATE

Anything correct so far.

a=> select tcl_max(3,7);
ERROR: Load of file /usr/postgres/lib/pltcl.so failed: /usr/lib/libtcl8.0.so:
undefined symbol: stat

There's something wrong with your Tcl installation. The Tcl
shared lib does not correctly reference the library where
stat() is in. It was linked with a missing -l...

You might try to link pltcl.so with the additional library.
Try adding -lm -lc.

Jan

--

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