<para>

All calls to functions that are written in a language other than

the current <quote>version 1</quote> interface for compiled

languages (this includes functions in user-defined procedural languages,

functions written in SQL, and functions using the version 0 compiled

language interface) go through a <firstterm>call handler</firstterm>

languages (this includes functions in user-defined procedural languages

and functions written in SQL) go through a <firstterm>call handler</firstterm>

function for the specific language. It is the responsibility of

the call handler to execute the function in a meaningful way, such

as by interpreting the supplied source text. This chapter outlines

PG_MODULE_MAGIC;

int64 execq(text *sql, int cnt);

PG_FUNCTION_INFO_V1(execq);

execq(text *sql, int cnt)

execq(PG_FUNCTION_ARGS)

{

char *command;

int cnt;

int ret;

uint64 proc;

/* Convert given text object to a C string */

command = text_to_cstring(sql);

command = text_to_cstring(PG_GETARG_TEXT_PP(1));

cnt = PG_GETARG_INT32(2);

SPI_connect();

SPI_finish();

pfree(command);

returnproc;

PG_RETURN_INT64(proc);

}

</programlisting>

<para>

(This function uses call convention version 0, to make the example

easier to understand. In real applications you should use the new

version 1 interface.)

</para>

<para>

This is how you declare the function after having compiled it into

a shared library (details are in <xref linkend="dfunc"/>.):