2 functions to extend gawk with

rextend.c

/*
 * rextend.c - 2 functions to extend gawk
 *
 * Aurelian Oancea, aurelian at locknet [dot] ro
 */

/*
 * Copyright (C) 2008 Aurelian Oancea
 *
 * 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 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "awk.h"
#include <openssl/md5.h>
#include <GeoIP.h>

/* compile with:
 * 
 * gcc -fPIC -shared -Wall -DHAVE_CONFIG_H -c -O -g -I.. -I/S/include rextend.c
 * ld -lssl -lGeoIP -L/S/lib -o rextend.so -shared rextend.o
 *
 * /S non standard path to GeoIP installation
 */

/* do_geoip --- given an IP, it finds the country code using GeoIP library[GPL] */
static NODE *
do_geoip(tree)
  NODE *tree;
{
  NODE *str;
  static GeoIP * gi = NULL;
  const char * ret;

  if (do_lint && get_curfunc_arg_count() != 1)
    lintwarn("geoip: called with incorrect number of arguments");

  str = get_argument(tree, 0);
  if(str!=NULL) {
    (void)force_string(str);
    if(gi==NULL)
      gi= GeoIP_new(GEOIP_STANDARD);
#if DEBUG
    printf("-> geoip(%s)\n", str->stptr);
#endif
    ret= GeoIP_country_code_by_name(gi, str->stptr);
    if(ret == NULL) {
#if DEBUG
      printf("ip: ``%s\" not found!\n", str->stptr);
#endif
      set_value(tmp_string("N/A", strlen("N/A")));
    } else {
      set_value(tmp_string((char *)ret, strlen(ret)));
    }

    free_temp(str);
  } else if(do_lint) {
    lintwarn("geoip: called with no arguments");
  }
  return tmp_number((AWKNUM) 0);
}

/* do_md5 --- calculates the md5 digest from the given string using the openssl library */
static NODE *
do_md5(tree)
  NODE *tree;
{

  unsigned char digest[16];
  char ret[32];
  int i;

  NODE *str;
  MD5_CTX ctx;

  if (do_lint && get_curfunc_arg_count() != 1)
    lintwarn("md5: called with incorrect number of arguments");

  str = get_argument(tree, 0);
  if(str!=NULL) {
    MD5_Init( &ctx );
    (void)force_string(str);
    MD5_Update( &ctx, str->stptr, strlen(str->stptr) );
    free_temp(str);
    MD5_Final( digest, &ctx );

    for( i=0; i<16; i++ )
      sprintf(ret+2*i, "%02x\n", digest[i]);

#if DEBUG
    printf("->%s\n", ret);
#endif

    set_value(tmp_string(ret, sizeof(ret)));
  }
  else if(do_lint) {
    lintwarn("md5: called with no arguments");
  }
  return tmp_number((AWKNUM) 0);
}

/* dlload --- load new builtins in this library */

NODE *
dlload(tree, dl)
NODE *tree;
void *dl;
{
  make_builtin("md5", do_md5, 1);
  make_builtin("geoip", do_geoip, 1);
  return tmp_number((AWKNUM) 0);
}