main.c

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

char * substr(char * string, int ini, int len){
    char * ret = malloc(len + 1);
    ret[len] = 0;
    int i = ini;
    int j = 0;
    while (i < strlen(string) && j < len){
        //strcpy(ret[i], string[i]);
        ret[j] = string[i];
        i++;
        j++;
    }
    return ret;
}

int strsearch(char * string, char * substring, int ini){
    char * aux = malloc(strlen(substring) + 1);
    aux[strlen(substring)] = 0;
    int i = ini;
    int j = 0;
    int k = 0;
    while (i < strlen(string)){
        j = 0;
        k = i;
        while (j < strlen(substring) && ( k < strlen(string) )){
            aux[j] = string[k];
            j++;
            k++;
        }
        if (strcmp(substring, aux) == 0)
            return i;
        i++;
    }
    return -1;
}

char * strreplace(char * str, char * oldstr, char * newstr){
    char * ret = malloc(strlen(str));
    char * aux;
    int pos = 0;
    int i = 0;
    strcpy(ret, str);

    pos = strsearch(ret, oldstr, 0);
    while (pos >= 0){
        aux = malloc(strlen(ret) -strlen(oldstr) + (strcmp(newstr, "") != 0? 0: strlen(newstr)));
        i = 0;
        strcpy(aux, "");
        while (i < pos){
            strncat(aux, &ret[i], 1);
            i++;
        }
        if (strcmp(newstr, "") != 0)
            strcat(aux, newstr);

        i = pos + strlen(oldstr);
        while (i < strlen(ret)){
            strncat(aux, &ret[i], 1);
            i ++;
        }
        free(ret);
        ret = aux;
        aux = NULL;
        pos = strsearch(ret, oldstr, 0);
    }

    return ret;

}

char* getAttr(char* attr, char* json, int inicio) {
  char* retorno;
  int auxint = 0;
  int auxlen = 0;
  int achoustring = 0;

  retorno = malloc(strlen(attr) + 3);
  strcpy(retorno, "\"");
  strcat(retorno, attr);
  strcat(retorno, "\"");
  retorno[strlen(attr) + 2] = 0;

  auxint = strsearch(json, retorno, inicio);
  free(retorno);
  retorno = NULL;
  if (auxint >= 0)
  {
      auxint = strsearch(json, ":", auxint + 1);
      if (auxint >= 0)
      {
          auxlen = strsearch(json, "\"", auxint + 1);
          if (auxlen >= 0){
            achoustring = 1;
          }

          if (auxlen < 0 || strsearch(json, "\"", auxint + 1) >= 0 && strsearch(json, "\"", auxint + 1) < auxlen){
              auxlen = strsearch(json, ",", auxint + 1);
              achoustring = 0;
          }
          if (auxlen < 0 || strsearch(json, "}", auxint + 1) >= 0 && strsearch(json, "}", auxint + 1) < auxlen){
              auxlen = strsearch(json,"}", auxint + 1);
              achoustring = 0;
          }
          if (auxlen < 0){
              auxlen = strsearch(json, "\n", auxint + 1);
              achoustring = 0;
          }
          if (achoustring == 1) // pega o fim da string
              auxlen = strsearch(json, "\"", auxlen + 1);

          if (auxlen - (auxint + 1) > 0)
          {
            retorno = malloc(auxlen);
            retorno = substr(json, auxint + 1, (auxlen - (auxint + 1)));
            retorno = strreplace(retorno, "\"", "");
          }
      }
  }
  return retorno;
}

struct PassoConfig {
  int pino;
  int tipo;
  int valor;
  struct PassoConfig *prox;
};
typedef struct PassoConfig PassoConfig;

struct Passo {
    int acao;
    int pino;
    int tipo;
    char * valor;
    struct Passo *prox;
};
typedef struct Passo Passo;

void insere(PassoConfig *lista, int pino, int tipo, int valor){
  PassoConfig *p = (PassoConfig *) malloc(sizeof(PassoConfig));
  p->pino=pino;
  p->tipo = tipo;
  p->valor = valor;

  p->prox=NULL;

  PassoConfig *aux;
  aux = lista;
  while (aux->prox!=NULL){
    aux=aux->prox;
  }

  aux->prox=p;
}

PassoConfig * fromJsonPassoConfig(char * json){
   PassoConfig *lista = NULL;
   int pino = 0, tipo = 0, valor = 0;
   char * aux;

   int idx_passo = strsearch(json, "{", 0);

   while (idx_passo >= 0){
      aux = getAttr("pino", json, idx_passo);
      if (aux == NULL || strcmp(aux, "") == 0){
        if (aux == NULL)
            aux = malloc(1);
        strcpy(aux, "0");
      }
      pino = atoi(aux);
      free(aux);
      aux = NULL;

      aux = getAttr("tipo", json, idx_passo);
      if (aux == NULL || aux == ""){
        if (aux == NULL)
            aux = malloc(1);
        aux = "0";
      }
      tipo = atoi(aux);
      free(aux);
      aux = NULL;

      aux = getAttr("valor", json, idx_passo);
      if (aux == NULL || aux == ""){
        if (aux == NULL)
            aux = malloc(1);
          aux = "0";
      }
      valor = atoi(aux);
      free(aux);
      aux = NULL;

      if (lista){
        insere(lista, pino, tipo, valor);

      }else {
         lista = (PassoConfig *) malloc(sizeof(PassoConfig));
         lista->pino=pino;
         lista->tipo=tipo;
         lista->valor = valor;

         lista->prox=NULL;
      }
      idx_passo = strsearch(json, "{", idx_passo + 1);
  }
    return lista;
}

void limpaLista(PassoConfig *lista){
    PassoConfig *aux;
    while (lista){
        aux=lista;
        lista=lista->prox;
        free(aux);
        aux = NULL;
    }
}
int main()
{
    //printf("%s", substr("Hello world!", 1, 3));
    //printf("\n%d", strsearch("Hello world!", "o", 0));
    //printf("\n%s", strreplace("Hello world!", "H", ""));
    PassoConfig *listConfig = fromJsonPassoConfig("[{\"pino\":\"2\",\"tipo\":\"10\",\"valor\":\"3\"},{\"pino\":\"2\",\"tipo\":\"40\",\"valor\":\"3\"},{\"pino\":\"2\",\"tipo\":\"80\",\"valor\":\"3\"}]");
    PassoConfig *aux;
//
        aux=listConfig;
        while (aux){
            printf("\n%d", aux->pino);
            printf("\n%d", aux->tipo);
            printf("\n%d", aux->valor);
            aux=aux->prox;
        }
    return 0;
}