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+---- Tema: Creando bibliotecas compartidas en C (/thread-1789.html)
Creando bibliotecas compartidas en C - tincho - 12-09-2024
Hola.
Hace un momento hice una prueba, le pedi a ChatGPT que me escribiera una biblioteca compartida en C que a su vez usa la librería LibreDWG y el resultado fue:
Código:
#include <stdio.h>
#include <stdlib.h>
#include <libredwg.h>
const char* list_blocks(const char* filename) {
static char result[4096];
DWG_Data *dwg;
int i;
// Inicializa la biblioteca
dwg = dwg_read(filename);
if (!dwg) {
return "Error reading DWG file.";
}
// Recorre los bloques y crea una lista
result[0] = '\0';
for (i = 0; i < dwg->num_blocks; i++) {
strcat(result, dwg->blocks[i].name);
strcat(result, "\n");
}
// Limpia
dwg_free(dwg);
return result;
}Por supuesto no funciono, por un lado en mi sistema no existe libredwg.h, pero se puede descargar el código fuente:
https://github.com/LibreDWG/libredwg
A ver si algún experto en C tiene ganas de experimentar un poco con esta herramienta.
Luego en el codigo fuente se puede ver un ejemlo que lista, en lugar de los "Blocks", los "Layers"
Código:
/*****************************************************************************/
/* LibreDWG - free implementation of the DWG file format */
/* */
/* Copyright (C) 2018-2019 Free Software Foundation, Inc. */
/* */
/* This library is free software, licensed under the terms of the GNU */
/* General Public License as published by the Free Software Foundation, */
/* either version 3 of the License, or (at your option) any later version. */
/* You should have received a copy of the GNU General Public License */
/* along with this program. If not, see <http://www.gnu.org/licenses/>. */
/*****************************************************************************/
/*
* dwglayers.c: print list of layers in a DWG
*
* written by Reini Urban
*/
#include "../src/config.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <getopt.h>
#ifdef HAVE_VALGRIND_VALGRIND_H
# include <valgrind/valgrind.h>
#endif
#include <dwg.h>
#include "common.h"
#include "bits.h"
#include "logging.h"
static int
usage (void)
{
printf ("\nUsage: dwglayers [-f|--flags] [--on] <input_file.dwg>\n");
return 1;
}
static int
opt_version (void)
{
printf ("dwglayers %s\n", PACKAGE_VERSION);
return 0;
}
static int
help (void)
{
printf ("\nUsage: dwglayers [OPTION]... DWGFILE\n");
printf ("Print list of layers.\n"
"\n");
#ifdef HAVE_GETOPT_LONG
printf (" -x, --extnames prints EXTNAMES (r13-r14 only)\n"
" i.e. space instead of _\n");
printf (" -f, --flags prints also flags:\n"
" 3 chars for: f for frozen, + or - for ON or OFF, l "
"for locked\n");
printf (" -o, --on prints only ON layers\n");
printf (" -h, --help display this help and exit\n");
printf (" --version output version information and exit\n"
"\n");
#else
printf (" -x prints EXTNAMES (r13-r14 only)\n"
" i.e. space instead of _\n");
printf (" -f prints also flags:\n"
" 3 chars for: f for frozen, + or - for ON or OFF, l "
"for locked\n");
printf (" -o prints only ON layers\n");
printf (" -h display this help and exit\n");
printf (" -i output version information and exit\n"
"\n");
#endif
printf ("GNU LibreDWG online manual: "
"<https://www.gnu.org/software/libredwg/>\n");
return 0;
}
int
main (int argc, char *argv[])
{
int error;
long i = 1;
int flags = 0, on = 0, extnames = 0;
char *filename_in;
Dwg_Data dwg;
Dwg_Object *obj;
Dwg_Object_LAYER *layer;
Dwg_Object_LAYER_CONTROL *_ctrl;
int c;
#ifdef HAVE_GETOPT_LONG
int option_index = 0;
static struct option long_options[] = { { "flags", 0, 0, 'f' },
{ "extnames", 0, 0, 'x' },
{ "on", 0, 0, 'o' },
{ "help", 0, 0, 0 },
{ "version", 0, 0, 0 },
{ NULL, 0, NULL, 0 } };
#endif
while
#ifdef HAVE_GETOPT_LONG
((c = getopt_long (argc, argv, "xfoh", long_options, &option_index))
!= -1)
#else
((c = getopt (argc, argv, "xfohi")) != -1)
#endif
{
if (c == -1)
break;
switch (c)
{
#ifdef HAVE_GETOPT_LONG
case 0:
if (!strcmp (long_options[option_index].name, "version"))
return opt_version ();
if (!strcmp (long_options[option_index].name, "help"))
return help ();
break;
#else
case 'i':
return opt_version ();
#endif
case 'x':
extnames = 1;
break;
case 'f':
flags = 1;
break;
case 'o':
on = 1;
break;
case 'h':
return help ();
case '?':
fprintf (stderr, "%s: invalid option '-%c' ignored\n", argv[0],
optopt);
break;
default:
return usage ();
}
}
i = optind;
if (i >= argc)
return usage ();
filename_in = argv[i];
memset (&dwg, 0, sizeof (Dwg_Data));
error = dwg_read_file (filename_in, &dwg);
if (error >= DWG_ERR_CRITICAL)
fprintf (stderr, "READ ERROR %s: 0x%x\n", filename_in, error);
obj = dwg_get_first_object (&dwg, DWG_TYPE_LAYER_CONTROL);
_ctrl = obj->tio.object->tio.LAYER_CONTROL;
for (i = 0; i < _ctrl->num_entries; i++)
{
char *name;
assert (_ctrl->entries);
assert (_ctrl->entries[i]);
obj = _ctrl->entries[i]->obj;
if (!obj || obj->type != DWG_TYPE_LAYER) // can be DICTIONARY also
continue;
assert (_ctrl->entries[i]->obj->tio.object);
layer = _ctrl->entries[i]->obj->tio.object->tio.LAYER;
if (on && (!layer->on || layer->frozen))
continue;
if (flags)
printf ("%s%s%s\t", layer->frozen ? "f" : " ", layer->on ? "+" : "-",
layer->locked ? "l" : " ");
if (extnames && dwg.header.from_version >= R_13 && dwg.header.from_version < R_2000)
{
if (!(name = dwg_find_table_extname (&dwg, obj)))
name = layer->name;
}
else
name = layer->name;
// since r2007 unicode, converted to utf-8
if (dwg.header.from_version >= R_2007)
{
char *utf8 = bit_convert_TU ((BITCODE_TU)name);
printf ("%s\n", utf8);
free (utf8);
}
else
printf ("%s\n", name);
fflush (stdout);
}
// forget about valgrind. really huge DWG's need endlessly here.
if ((dwg.header.version && dwg.num_objects < 1000)
#if defined __SANITIZE_ADDRESS__ || __has_feature(address_sanitizer)
|| 1
#endif
#ifdef HAVE_VALGRIND_VALGRIND_H
|| (RUNNING_ON_VALGRIND)
#endif
)
dwg_free (&dwg);
return error >= DWG_ERR_CRITICAL ? 1 : 0;
}