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PostgreSQL PL/C Functions

Hi ,

Here is my first PL/C Function. Find the Steps How to create and implement. 

Step 1
======
-bash-3.2$ pwd
/opt/PostgresPlus/9.0AS
-bash-3.2$ more concat_text.c
#include "postgres.h"
#include "fmgr.h"
#include <string.h>
#include <unistd.h>
#ifdef PG_MODULE_MAGIC
PG_MODULE_MAGIC;
#endif

PG_FUNCTION_INFO_V1(concat_text);
Datum
concat_text(PG_FUNCTION_ARGS)
{
    text  *arg1 = PG_GETARG_TEXT_P(0);
    text  *arg2 = PG_GETARG_TEXT_P(1);
    int32 new_text_size = VARSIZE(arg1) + VARSIZE(arg2) - VARHDRSZ;
    text *new_text = (text *) palloc(new_text_size);
    system("touch /tmp/table.txt");
    SET_VARSIZE (new_text,new_text_size);
    memcpy(VARDATA(new_text), VARDATA(arg1), VARSIZE(arg1) - VARHDRSZ);
    memcpy(VARDATA(new_text) + (VARSIZE(arg1) - VARHDRSZ),
           VARDATA(arg2), VARSIZE(arg2) - VARHDRSZ);
    PG_RETURN_TEXT_P(new_text);
}

Step 2
=======
-bash-3.2$ more Makefile
PG_CONFIG = /opt/PostgresPlus/9.0AS/bin/pg_config
MODULES = concat_text
PGXS := $(shell $(PG_CONFIG) --pgxs)
include $(PGXS)

Step 3
======
make and .so file to $PGHOME/lib  or $PGHOME/lib/postgres/

Step 4
======
edb=# CREATE OR REPLACE FUNCTION concat_text(text, text) RETURNS text                                                                                             AS 'concat_text.so', 'concat_text'                                                                                                                           LANGUAGE C STRICT;
CREATE FUNCTION

Step 5
======
edb=# select concat_text('Dinesh ','Kumar');
 concat_text
--------------
 Dinesh Kumar
(1 row)

--Dinesh

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