Searching a binary file

[rhysmeister]

I am trying to write a function which searches a binary file for the occurance of a particular string of characters. I've made some progress but have got a little stuck. Here's what I have come up with so far

void searchRandomObjectForName(string fname)
    
{
    	int index = 0;
    	string search, name;
    	cout << "Enter a string to search the file for: " << flush;
         cin >> search;
    	ifstream is(fname.c_str(), ios::binary); // open file to read

         // while we can read from the file
         while(is.read(reinterpret_cast<char *>(&name), sizeof(int)))
         {
      	    // search here, print out string and position in the file
            // or print "string not found message."
         }
          is.close(); // close file when done
    	cout << endl;
}

Can anybody help out?

[Salem]

http://cboard.cprogramming.com/showthread.php?t=13473

[kuphryn]

One solution is strstr().

Kuphryn

[Hammer]

The file is binary, so I guess it'd be safe to assume that strings aren't the best thing to store data in.

Here's one way of doing what you want

 #include <iostream>
 #include <fstream>
 
 int main()
 {  
   char  LookForArray[] = "\x11\x12\x13";
   int   Len = sizeof(LookForArray) - 1;
   int   LookForByte = 0;
   int   c;
   std::ifstream is("myfile.bin", std::ios::binary);
   
   while (LookForByte < Len && (c = is.get()) != EOF)
   {
 	if (c == LookForArray[LookForByte])
 	  LookForByte++;
 	else LookForByte = 0;
   }
   
   if (LookForByte == Len)
   {
 	std::cout <<"item was found" <<std::endl;
   }
   else
   {
 	std::cout <<"item was not found" <<std::endl;
   }
   
   is.close();
 }

[kuphryn]

Another solution is memchr().

Kuphryn