Traitement sur chaine du caractere en C

#include <stdio.h>
void main()
{
    FILE *fichier=NULL,*owned=NULL;char ch[100];
    owned=fopen("owned.txt","w+");
    fichier=fopen("site.txt","r+");
    while (fgets(ch,50,fichier)!=NULL)
    {



   const char* av = ". 	";
   const char* ap = "	";

   char* ch1 = strstr(ch,av);
   if (ch1)
   {
      char value[100];
      strcpy(value,ch1 + strlen(av));

      char* ch2 = strstr(value,ap);

      if (ch2) value[ch2 - value] = 0;

      fprintf(owned,"%s\n",value);
   }
   }
       fclose(owned);
       fclose(fichier);
}