Thread: String appears to change on its own

Hi i am working on this program. I have looked over it and i cannot determine an explanation for its behavior. Can someone help explain why and how to overcome this issue? Thanks a bunch.

Code:

#include <string.h>
#include <stdio.h>

int
main ()
{
  char *the_message = "42.77417833333333|-78.31375166666667";
  char latitude[17];
  char longitude[17];
  int lat_counter_x = 0;
  int long_counter_x = 0;
  int long_counter_y = 0;
  int pipe_location;

  for (lat_counter_x = 0; lat_counter_x <= strlen (the_message);
       lat_counter_x++)
    {
      if (the_message[lat_counter_x] == '|')
        {
          pipe_location = lat_counter_x;        //shows character location of | - separates lat/long numbers
        }
    }

  if (pipe_location)
    {
      for (lat_counter_x = 0; lat_counter_x < (pipe_location - 1);
           lat_counter_x++)
        {
          latitude[lat_counter_x] = the_message[lat_counter_x];
        }
      latitude[lat_counter_x + 1] = '\0';
    }
  printf ("Latitude: %s\n", latitude);  // displays properly 42.77417833333333
  for (long_counter_x = (pipe_location + 1);
       long_counter_x <= strlen (the_message); long_counter_x++)
    {
      longitude[long_counter_y] = the_message[long_counter_x];
      long_counter_y++;
    }
  longitude[long_counter_y] = '\0';
  printf ("Longitude: %s\n", longitude);        // displays properly -78.31375166666667
  printf ("Latitude: %s\n", latitude);  //the number changes .... why? - latitude is now the last char of longitude
  printf ("Longitude: %s\n", longitude);        // displays properly -78.31375166666667
}

//If i comment out the second for loop, latitude is not affected.

/* Output
Latitude: 42.7741783333333
Longitude: -78.31375166666667
Latitude: 7
Longitude: -78.31375166666667
*/

Code:

         1111111111
1234567890123456789

-78.31375166666667n

The n is the \0 character. What are the odds that a 17-character array is long enough to hold this? (Hint: not good.)

Why don't you use standard function like strchr(),strcpy() ?

LOL, Is it pseudo Code?!
Modifying string literal is Undefined Behavior.

Code:

  char *the_message; //= "42.77417833333333|-78.31375166666667";  
  char *latitude = the_message;
  char *longitude = strchr(the_message,'|');
  the_message[longitude++] = 0;
  printf("Lat = %s  Long = %s\n",latitude,longitude);

Actually I'm a bit concerned that someone wouldn't know what to do anyway since a pointer is being used as an index here. Maybe the_message[longitude - latitude] = 0; is more correct.