MAC OS app - reading contents from a file

Since the file reading operations will take good amount of time, It is good idea to start that in a separate thread

[NSThread detachNewThreadSelector:@selector(scanAndFindLocationChangeReports:) toTarget:self withObject:absString];

-(void) scanAndFindLocationChangeReports:(NSString*) filePath

{

    const char* filePathCStr = [filePath cStringUsingEncoding:NSUTF8StringEncoding];

    FILE *file = fopen(filePathCStr, "r");

    // check for NULL

    while(!feof(file))

    {

        NSString *line = readLineAsNSString(file);

        // do stuff with line; line is autoreleased, so you should NOT release it (unless you also retain it beforehand)

        NSLog(@"-- File Line is :%@",line);

    }

    fclose(file);

    [self performSelectorOnMainThread:@selector(updateLabels) withObject:nil waitUntilDone:NO];

}

NSString *readLineAsNSString(FILE *file)

{

    char buffer[4096];

    

    // tune this capacity to your liking -- larger buffer sizes will be faster, but

    // use more memory

    NSMutableString *result = [NSMutableString stringWithCapacity:256];

    

    // Read up to 4095 non-newline characters, then read and discard the newline

    int charsRead;

    do

    {

        if(fscanf(file, "%4095[^\n]%n%*c", buffer, &charsRead) == 1)

            [result appendFormat:@"%s", buffer];

        else

            break;

    } while(charsRead == 4095);

    

    return result;

}