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Thread: Trying to make functions in 'C'

Trying to make functions in 'C'

From
"fabian baena"
Date:
I'm tying to learn how to make function in 'C'.
I'm trying to compile a program I made in 'C'.
The command I gave were:

% gcc -fPIC -c addone.c -I/usr/local/pgsql/include
% ld -G -Bdynamic -o addone.so addone.o

and created the function in postgres like this:

         CREATE FUNCTION add_one(int4) RETURNS int4
              AS './addone.so' LANGUAGE 'c';


The function I made looks like this:

#include "postgres.h"

int
add_one(int arg)
{
     return arg + 1;
}

But when I try to test the function in postgres I recieve this error:

ERROR:  stat failed on file ./addone.so
ERROR:  stat failed on file ./addone.so
Can anyone tell where did I make a mistake?
I have a linux on a PC.

Thank you.


Fabian.


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Re: [GENERAL] Trying to make functions in 'C'

From
selkovjr@mcs.anl.gov
Date:
> I'm tying to learn how to make function in 'C'.
> I'm trying to compile a program I made in 'C'.
> The command I gave were:
>
> % gcc -fPIC -c addone.c -I/usr/local/pgsql/include
> % ld -G -Bdynamic -o addone.so addone.o
>
> and created the function in postgres like this:
>
>          CREATE FUNCTION add_one(int4) RETURNS int4
>               AS './addone.so' LANGUAGE 'c';
                   ^^^^^^^^^^^^^
one must provide an absolute path here

--Gene

Re: [GENERAL] Trying to make functions in 'C'

From
tolik@icomm.ru (Anatoly K. Lasareff)
Date:
>>>>> "fb" == fabian baena <fabbaena@hotmail.com> writes:

 fb> I'm tying to learn how to make function in 'C'.
 fb> I'm trying to compile a program I made in 'C'.
 fb> The command I gave were:

 fb> % gcc -fPIC -c addone.c -I/usr/local/pgsql/include
 fb> % ld -G -Bdynamic -o addone.so addone.o

 fb> and created the function in postgres like this:

 fb> CREATE FUNCTION add_one(int4) RETURNS int4
 fb> AS './addone.so' LANGUAGE 'c';


 fb> The function I made looks like this:

 fb> #include "postgres.h"

 fb> int
 fb> add_one(int arg)
 fb> {
 fb> return arg + 1;
 fb> }

 fb> But when I try to test the function in postgres I recieve this error:

 fb> ERROR:  stat failed on file ./addone.so
 fb> ERROR:  stat failed on file ./addone.so
 fb> Can anyone tell where did I make a mistake?
 fb> I have a linux on a PC.

Pehaps not 'int', but 'int4' in argument and return type? Except this
I think your example is right.

--
Anatoly K. Lasareff              Email:       tolik@icomm.ru
Senior programmer

Re: [GENERAL] Trying to make functions in 'C'

From
selkovjr.mcs.anl.gov@mcs.anl.gov
Date:
> >>>>> "fb" == fabian baena <fabbaena@hotmail.com> writes:
>
>  fb> I'm tying to learn how to make function in 'C'.
>  fb> I'm trying to compile a program I made in 'C'.
>  fb> The function I made looks like this:
>
>  fb> #include "postgres.h"
>
>  fb> int
>  fb> add_one(int arg)
>  fb> {
>  fb> return arg + 1;
>  fb> }
>
> Pehaps not 'int', but 'int4' in argument and return type? Except this
> I think your example is right.

As far as return types, make sure you get what you want by
checking how types are typedef'ed in postgres.h

The safest way to add your own code would be what Fabian is trying to
accomplish -- by using the prototypes from tutorial.


--Gene

problem with LOAD

From
abdelkrim
Date:
hello every body

i have some problem with LOAD command

postgres=> LOAD '/usr/local/pgsql/complex.so';
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.
$>>

I build complex.so by:

>> gcc -I../include -I../backend   -O2 -m486 -pipe  -Wall
-Wmissing-prototypes -I../interfaces/libpq -I../../include   -c
complex.c -o complex.o
>> ld -x -r -o complex.o.obj complex.o
>> ranlib complex.so.pic
>> ld -x -Bshareable -o complex.so complex.so.pic

I use FreeBSD-3.1 with PostgreSQL 6.4.2

thanks

Re: [INTERFACES] problem with LOAD

From
Oleg Bartunov
Date:
This is a known problem with FreeBSD-3.1 and PostgreSQL I had too with
6.5 cvs version. I suppose you use FreeBSD elf ? Take a look to
ports for freebsd-elf specific patches or just change

src/Makefile.shlib

ifeq ($(PORTNAME), freebsd)
  ifdef BSD_SHLIB
    install-shlib-dep   := install-shlib
    ifdef ELF_SYSTEM
      shlib             := lib$(NAME)$(DLSUFFIX).$(SO_MAJOR_VERSION)
      LDFLAGS_SL        := -x -shared -soname $(shlib)
    else
      shlib             := lib$(NAME)$(DLSUFFIX).$(SO_MAJOR_VERSION).$(SO_MINOR_VERSION)
      LDFLAGS_SL        := -x -Bshareable -Bforcearchive
    endif
    CFLAGS              += $(CFLAGS_SL)
  endif
endif

and makefiles/Makefile.freebsd

ifdef ELF_SYSTEM
LDFLAGS+=       -export-dynamic
endif

%.so: %.o
ifdef ELF_SYSTEM
        $(LD) -x -shared -o $@ $<
else
        $(LD) -x -r -o $<.obj $<
        @echo building shared object $@
        @rm -f $@.pic
        @${AR} cq $@.pic order $<.obj | tsort
        ${RANLIB} $@.pic
        @rm -f $@
        $(LD) -x -Bshareable -Bforcearchive -o $@ $@.pic
endif

This works for me !


    Regards,

        Oleg

PS.
These patches are already applied to current 6.5 sources.

On Thu, 20 May 1999, abdelkrim wrote:

> Date: Thu, 20 May 1999 18:06:30 +0000
> From: abdelkrim <haj@idianet.net>
> To: pgsql-general@postgresql.org, pgsql-interfaces@postgresql.org
> Subject: [INTERFACES] problem with LOAD
>
> hello every body
>
> i have some problem with LOAD command
>
> postgres=> LOAD '/usr/local/pgsql/complex.so';
> 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.
> $>>
>
> I build complex.so by:
>
> >> gcc -I../include -I../backend   -O2 -m486 -pipe  -Wall
> -Wmissing-prototypes -I../interfaces/libpq -I../../include   -c
> complex.c -o complex.o
> >> ld -x -r -o complex.o.obj complex.o
> >> ranlib complex.so.pic
> >> ld -x -Bshareable -o complex.so complex.so.pic
>
> I use FreeBSD-3.1 with PostgreSQL 6.4.2
>
> thanks
>
>
>

_____________________________________________________________
Oleg Bartunov, sci.researcher, hostmaster of AstroNet,
Sternberg Astronomical Institute, Moscow University (Russia)
Internet: oleg@sai.msu.su, http://www.sai.msu.su/~megera/
phone: +007(095)939-16-83, +007(095)939-23-83

Re: [GENERAL] Trying to make functions in 'C'

From
Jonathan Davis
Date:
hello


CREATE SEQUENCE seq

        INCREMENT       1
        MINVALUE        1
        START           1
;

CREATE TABLE T (
 index  int  primary key UNIQUE DEFAULT nextval('seq'),
 f1    char(5),
 f2    char(5)

);

CREATE TABLE T1 (
 f3    char(5),
 f4    char(5),
 f5    char(5)

) INHERITS (T);

CREATE TABLE  T2(
 cp1      char(5),
 cp2  char(5)
) INHERITS (T);


INSERT INTO T1 VALUES ( nextval('seq'), 'joe', 'joe', 'joe', 'joe', 'joe');
INSERT INTO T1 VALUES ( nextval('seq'), 'davis', 'davis', 'davis', 'davis',
'davis');
INSERT INTO T1 VALUES ( nextval('seq'), 'ba', 'ba', 'ba', 'ba', 'ba');

INSERT INTO T2 VALUES  ( nextval('seq'), 'aw', 'aw', 'aw', 'aw');
INSERT INTO T2 VALUES  ( nextval('seq'), 'es', 'es', 'es', 'es');

SELECT * FROM T*;

this request give me only the fields in table T but I want to give me all
fiels in T1 and T2
how ?

thanks

pb with select

From
Jonathan Davis
Date:
Jonathan Davis wrote:

> hello
>
> CREATE SEQUENCE seq
>
>         INCREMENT       1
>         MINVALUE        1
>         START           1
> ;
>
> CREATE TABLE T (
>  index  int  primary key UNIQUE DEFAULT nextval('seq'),
>  f1    char(5),
>  f2    char(5)
>
> );
>
> CREATE TABLE T1 (
>  f3    char(5),
>  f4    char(5),
>  f5    char(5)
>
> ) INHERITS (T);
>
> CREATE TABLE  T2(
>  cp1      char(5),
>  cp2  char(5)
> ) INHERITS (T);
>
> INSERT INTO T1 VALUES ( nextval('seq'), 'joe', 'joe', 'joe', 'joe', 'joe');
> INSERT INTO T1 VALUES ( nextval('seq'), 'davis', 'davis', 'davis', 'davis',
> 'davis');
> INSERT INTO T1 VALUES ( nextval('seq'), 'ba', 'ba', 'ba', 'ba', 'ba');
>
> INSERT INTO T2 VALUES  ( nextval('seq'), 'aw', 'aw', 'aw', 'aw');
> INSERT INTO T2 VALUES  ( nextval('seq'), 'es', 'es', 'es', 'es');
>
> SELECT * FROM T*;
>
> this request give me only the fields in table T but I want to give me all
> fiels in T1 and T2
> how ?
>
> thanks