/***************************************************************************
 *                         exe_builtin_mod.c -  description
 *                            -------------------
 *   begin                : Mon 19 Dec 2005 04:20:14 PM EST
 *   copyright            : (C) 2005 by Terry D. Boldt
 *   email                : fastsnip-wm1@yahoo.com
 ***************************************************************************/

/***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/
/*
 *
 *   QTAwk plugin function to demonstrate executing QTAwk builtin functions
 */

#include "QTAwk_plugins.h"
#include <string.h>
#include <stdlib.h>
#include <stdio.h>

/* define some useful constants
 */
#define TRUE  1
#define FALSE 0

/* define End Of String marker
 */
#define EOS '\x000'

/* define initialization function
 */
unsigned init_exebuiltin(
void)
{
    /* array of pointers to string with argument names for loaded functions
     * Here both functions take a single string function
     */
    unsigned char *arguments[] = {
                    "lcl_time",
                    NULL
                    };

    /* declare error return variable
     */
    unsigned char *reg_err;

    /* call function to initialize for installing dynamic function(s)
     */
    QTAwk_register_function_count(3);

    /* now call function to register each dynamic function to load
     *
     * Note that 'QTAwk_register_function' returns a pointer to a string or NULL
     * if no error in registering function. Here we are ignoring the return value
     * until returning from the call.
     * We "should" examine the return value for every call to 'QTAwk_register_function'
     * and report any errors.
     */
    reg_err = QTAwk_register_function("exe_builtin_mod_version",NULL,FALSE);
    reg_err = QTAwk_register_function("exe_builtin",NULL,FALSE);
    reg_err = QTAwk_register_function("get_dup",NULL,FALSE);

    return reg_err ? -1 : 0;
} /* init_exebuiltin */

/* function registered to accomplish actual work.
 *
 * All dynamically loaded functions have the following prototype form:
 *
 *      Variable_ptr loaded_function(unsigned argument_count);
 *
 * Where 'Variable_ptr' is a QTAwk variable defined in the QTAwk plugin
 *  header file "QTAwk_plugins.h"
 *  Do NOT manipulate the fields in the structure directly. Use the function
 *  calls defined in "QTAwk_plugins.h" for that purpose.
 *
 *
 *
 */

/* version string
 */
static unsigned char version_string[] = "Execute Builtin Function Module, Version 1.00";

/* function to return module version string
 */
Variable_ptr exe_builtin_mod_version(
void)
{
    Variable_ptr   retval;

    retval = QTAwk_get_variable_set((void *)version_string,STRING_VAL);

    return retval;
} /* exe_builtin_mod_version */
/*
 * Execute builtin function srange
 *
 */
Variable_ptr exe_builtin(
unsigned     arg_cnt)
{
    Variable_ptr   retval;
    Variable_ptr   chr1,
                   chr2;
    qta_long       elem_value;
    unsigned char  chr;

    /* get first character in range
     */
    chr = 'A';
    chr1 = QTAwk_get_variable_set((void *)&chr,CHAR_VAL);

    /* get second character in range
     */
    chr = 'z';
    chr2 = QTAwk_get_variable_set((void *)&chr,CHAR_VAL);

    /* the following call illustrates an incorrect argument list. There is one
     * argument for the builtin function, but 2 specified (the correct number for the
     * builtin function is 2). Uncommenting the following line, compiling and
     * executing will result in a run-time error from QTAwk.
     */
    /* retval = QTAwk_execute_builtin_function(QTAWK_SRANGE,2,chr1,NULL);   */

    /* the following call illustrates an incorrect argument list. There is one
     * argument for the builtin function, but 2 specified (the correct number for the
     * builtin function is 2). Uncommenting the following line, compiling and
     * executing will result in a run-time error from QTAwk.
     */
    /* retval = QTAwk_execute_builtin_function(QTAWK_SRANGE,2,chr1,chr2);   */

    /* the following is the correct argument list for the call. It has the correct number of
     * arguments for the builtin function, the correct number specified, and the terminating
     * NULL pointer - which is NOT included in the argument count specified.
     */
    retval = QTAwk_execute_builtin_function(QTAWK_SRANGE,2,chr1,chr2,NULL);

    return retval;
} /* exe_builtin */


/* Get alpha characters from POSIX array and duplicate
 */
Variable_ptr get_dup(
unsigned     arg_cnt)
{
    Variable_ptr   retval;
    Variable_ptr   alpha;

    alpha = QTAwk_get_named_variable("POSIX");

    alpha = QTAwk_get_array_element(alpha,"s","alpha");

    retval = QTAwk_dup(alpha);

    return retval;
} /* get_dup */

/* exit function - executed before unloading module
 * Using default function name here.
 */
unsigned QTAwk_exit_load_module(
void)
{
    printf("Unloading Execute built function Demo module.\n");
} /* QTAwk_exit_load_module */