Hi,

I can't free the memory of some pointers ( *cad2 and *res) in
netman-gtk3. This is what i get:

~$ gcc main.c -o main

~$ ./main
*** Error in `./main': munmap_chunk(): invalid pointer:
0x0000000001bfdab4 ***
Aborted

See the comented lines 119 and 120 in the attached file.

The textual output of this applications shows the caracteristics of the
available active wifis.

Any hints?

    Aitor.

Note: you need to install the backend of netman.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int N;
int scan_dim();
void scan_buffer (char **ptr, char *command, char *name, char *str1, char *str2);

int main(int argc, char **argv)
{
int i;
char **_essid, **_address, **_quality;
    
N=scan_dim();

_essid = (char**)malloc(N*sizeof(char*));
if(!_essid) {printf("Fallo de asignación de memoria\n"); exit(-1);}
    
_address = (char**)malloc(N*sizeof(char*));
if(!_address) {printf("Fallo de asignación de memoria\n"); exit(-1);}

_quality = (char**)malloc(N*sizeof(char*));
if(!_quality) {printf("Fallo de asignación de memoria\n"); exit(-1);}

scan_buffer (_essid, "/usr/lib/netman/bin/backend 8", "ESSID:", "\"", "\"");
scan_buffer (_quality, "/usr/lib/netman/bin/backend 8", "Quality=", "=" , "Signal level");
scan_buffer (_address, "/usr/lib/netman/bin/backend 8", "Address:", " " , "\"");

  for(i=0; i<N; i++)
  {
    printf("%s\n", _essid[i]);
    free(_essid[i]);
  }

  for(i=0; i<N; i++)
  {
    printf("%s\n", _address[i]);
    free(_address[i]);
  }

  for(i=0; i<N; i++)
  {
    printf("%s\n", _quality[i]);
    free(_quality[i]);
  }

  free(_essid);    
  free(_address);
  free(_quality);
  system("rm -f output");    
  return 0;
}

void scan_buffer (char **ptr, char *command, char *name, char *str1, char *str2)
{
FILE *fp;
char *cad1, *cad2, *res;

  cad1=(char*)malloc(1024*sizeof(char));
      if(!cad1) {printf("Fallo de asignación de memoria\n"); exit(-1);}

  cad2=(char*)malloc(1024*sizeof(char));
      if(!cad2) {printf("Fallo de asignación de memoria\n"); exit(-1);}

  res=(char*)malloc(1024*sizeof(char));
      if(!res) {printf("Fallo de asignación de memoria\n"); exit(-1);}  

fp = fopen("output", "r");
if(!fp) exit(-1);

  int cont=0;
  while (fgets(cad1, 1024, fp))
  {
    if(strstr((char *) cad1, name))
       {
         cad2 = strstr((char *) cad1, name);  
         res  = strstr((char *) cad2, str1);

         if(name!="Address:")
         {  
          int bool=0;
          int i=0;
          int n,m;
          while ((bool!=1) && (res[i]!='\0'))
            {
             if(str2[0]==res[i])
                {
                  m=i; n=0;
                while ((bool!=1) && (str1[n]==res[m]))
                        {
                          n++; m++;
                          if (n == strlen(res)) bool=1;
                        }
                }
             i++;
            }

          for (i=(m-n); res[i]!='\0';i++) res[i]='\0';
         }
         else res[18]='\0';

         int j=0;        
         while(j<strlen(res)) {res[j]=res[j+1]; j++;}
         res[j]='\0';

         j=1;
         while(res[strlen(res)-j]==' ') {res[strlen(res)-j]='\0'; j++;}

         ptr[cont] = (char*)malloc(strlen(res)*sizeof(char));
         if(!ptr[cont]) {printf("Fallo de asignación de memoria\n"); exit(-1);}

         strcpy(ptr[cont], res);
         ptr[cont][strlen(res)]='\0';
         cont++;
       }
  }

free(cad1);
// free(cad2);
// free(res);
fclose(fp);
return;
}

int scan_dim ()
{
FILE *fp, *fp1;
char *cad1, *cad2;

  cad1=(char*)malloc(1024*sizeof(char));
      if(!cad1) {printf("Fallo de asignación de memoria\n"); exit(-1);}

  cad2=(char*)malloc(1024*sizeof(char));
      if(!cad2) {printf("Fallo de asignación de memoria\n"); exit(-1);}

fp = popen("/usr/lib/netman/bin/backend 8", "r");
if(!fp) exit(-1);

fp1 = fopen("output", "w");
if(!fp1) exit(-1);

  int cont=0;
  while (fgets(cad1, 1024, fp))
  {
    if(strstr((char *) cad1, "Address:"))
       {
          cad2 = strstr((char *) cad1, "Address:");
          fprintf(fp1, "%s", cad2);  
         cont++;
       }
    else if(strstr((char *) cad1, " "))
            {
              cad2 = strstr((char *) cad1, " ");
              fprintf(fp1, "%s", cad2);  
            } 
  }

pclose(fp);
fclose(fp1);
return cont;
}