Thread: Seg fault issue

Hey guys.

I am creating a small type and search program and it compiles ok. If I enter the correct word it displays the character string fine then terminates. However, if I enter an incorrect word, it freezes and throws a seg-fault. After using the debugger, the error line is the if statement header. Here is the code:

Code:

#include <iostream>
#include <cstring>

// main function - driver //////////////////////////////////////////////////////
//
int main ( void )
{
   int i;
   char *pSearchGrid[][ 2 ] = 
   {
      "pencil", "A writing device",
       "amelle", "One of the Sugababes" ,
       "computer", "Hardware device that uses software" ,
       "phone", "Device that makes and recieves telephone calls" ,
       "picture", "Drawn or computerized image",
       "", "" 
   };
   
   char word[ 80 ];
   
   std::cout << "Enter a word to find: ";
   std::cin >> word;
   
   for ( i = 0; pSearchGrid[ i ][ 0 ]; i++ )
   {
       if ( !strcmp ( pSearchGrid[ i ][ 0 ], word ))
       {
          std::cout << std::endl << pSearchGrid[ i ][ 1 ] << std::endl;
          break;
       }
   }
   
   if ( !*pSearchGrid[ i ][ 0 ] )  // SEG FAULT DEBUG BREAK HERE
   {
      std::cout << word << " not found...\n";
   }
          
   std::cin.get(); // freeze console output window
   std::cin.ignore();
   
   return 0; // return value from int main
}

I have looked over it and cannot see why it keeps breaking here. Can you see what I have done wrong? I appreciate any help.

Apparently the end terminator "" has a non-null address and doesn't stop the loop where you want to. You probably want to check if the first character of that string is '\0'.

Unless you absolutely need to do it that way, an std::map would be much more appropriate.

Originally Posted by anon

Apparently the end terminator "" has a non-null address and doesn't stop the loop where you want to. You probably want to check if the first character of that string is '\0'.

Thanks!

I changed the for loop line to

Code:

for ( i = 0; *pSearchGrid[ i ][ 0 ]; i++ )

and its working now

And Desolation, we havent covered maps yet but when we do I am sure I will understand your meaning further. Thank you for the advice guys.

Code:

   char *pSearchGrid[][ 2 ] = 
   {
      "pencil", "A writing device",
       "amelle", "One of the Sugababes" ,
       "computer", "Hardware device that uses software" ,
       "phone", "Device that makes and recieves telephone calls" ,
       "picture", "Drawn or computerized image",
       NULL, NULL
   };

would be a better change, as:
1. It makes it obvious that it's the end of the list.
2. Takes up (slightly) less space.

--
Mats