Thread: Reading in File Help

Hi, I'm trying to read from a file and I'm getting a segmentation fault, can someone help me with what I'm doing wrong:

My .txt file looks exactly like this:

Code:

-CD-
Artist: Outkast
Title: Stankonia
Year: 1997

-CD-
Artist: Jay Z
Title: Reasonable Doubt
Year: 1993

-CD-
Artist: Atmosphere
Title: Overcast
Year: 1995

Those years might not be right but whatever, its a test

Now this is my code:

Code:

#include <iostream.h>
#include <fstream.h>


int main()
{
  ifstream infile;
  char* line = new char[512];
  char* temp = new char[100];
  char* garbage = new char[50];
  char* artist = new char[50];
  char* title = new char[50];
  char* year = new char[50];

  infile.open("databaseFile.txt");

  while ( infile.peek() != EOF )
    {

      infile.getline(garbage,100);

      infile.getline(line,512);

      temp = strtok(line, " ");
      strcpy(garbage,temp);

      temp = strtok(NULL, "\n");
      strcpy(artist, temp);

      temp = strtok(NULL, " ");
      strcpy(garbage,temp);

      temp = strtok(NULL, "\n");
      strcpy(title,temp);

      temp = strtok(NULL, " ");
      strcpy(garbage,temp);

      temp = strtok(NULL, "\n");
      strcpy(year,temp);

      infile.getline(garbage,100);

    }

}

The first part should ignore the first line because that just says "-CD-". Then I tried to strtok with the delimeter of " " and ignore that part because thats the part that says "Artist:", "Title: ", and "Year: ". Then I try to strtok with "\n" and save that as the actual artist, title, and year. I strtok'ed with "\n" because artists and titles could have a space in their name so if I strtok with the " " it will break it up. But I'm getting a segmentation fault and I put some cout's in there to find out how far it got and it dumps the core right after it strtok's the artist.

Can someone please Help!

Check this out swayp, you shall be brought to shore once again:

Code:

/*
  WARNING: I used goto, goto is bad.  I used goto because I was too lazy
  to understand the logicalness of the while() loop
*/

#include <iostream>
#include <fstream>
#include <string>
#include <vector>

using std::cout;
using std::endl;
using std::ifstream;
using std::string;
using std::vector;

// Extract tags from text file
string extractTag( ifstream * in, string startAfter, string endWhen );


int main( )
{
  // sz = the temperary string that gets extracted from the stream
  // szT = the temperary string that works with the tag innards

  string sz;
  string szT;

  // Create and open an input stream to the CD database

  ifstream in;
  in.open( "CDdb.txt" );

  // Make sure the CD database opened successfully

  if( !in.is_open( ) )
  {
      cout << "Could not open file" << endl;
      return 1;
  }

  // Prepare all of the information for the database
  // A = Artists
  // T = Title of CD
  // Y = Year of CD

  vector<string> A;
  vector<string> T;
  vector<string> Y;

  // Read all of the information from the CD database:

  while( !in.eof( ) )
  {
      // Extract Artist tag

      sz = extractTag( &in, "Artist:", "Title:" );
      if( sz.empty( ) )
        break;
      A.push_back( sz );

      // Extract Title tag:

      sz = extractTag( &in, "", "Year:" );
      if( sz.empty( ) )
        break;
      T.push_back( sz );

      // Extract Year tag:

      sz = extractTag( &in, "", "-CD-" );
      if( sz.empty( ) )
        break;
      Y.push_back( sz );
  }

  // Close the file stream

  in.close( );

  // Output all of the artists, titles, and years

  cout << "Artists: " << endl;
  for( size_t i = 0; i < A.size( ); i++ )
    cout << A[i] << endl;

  cout << "------------\nTitles: " << endl;
  for( size_t i = 0; i < T.size( ); i++ )
    cout << T[i] << endl;

  cout << "------------\nYears: " << endl;
  for( size_t i = 0; i < Y.size( ); i++ )
    cout << Y[i] << endl;

  // Return successfully

  return 0;
}


// Extract tags from text file
string
extractTag ( ifstream * in, // The stream we're extracting data from
            string s,       // Start extracting data after this string
            string e )      // Stop extracting data once we hit this "other" tag
{
  // sz = Create a string for comparing when we need to start extracting
  // szM = The master string that we return back as the tag's innards

  string sz;
  string szM;

  // Start extracting until we hit the start extracting string
  // Make sure the starting isn't empty though, that means we
  // just start scanning for tag innards immediately

  if( s.empty( ) )
    goto SkipThisBS;
  while( ( *in ) >> sz )
  {
      if( !sz.compare( s ) )
        break;
  }
SkipThisBS:

  // Make sure the stream is not empty

  if( ( *in ).eof ( ) )
    return "";

  // Start extracting the real stuff until we hit the ending tag

  while( ( *in ) >> sz && sz != e )
    szM += sz;

  // Return the innards of the tag

  return szM;
}