Thread: Program reading data of previous 'record' into the new one to be added

Basically,
I have a program that reads a file and stores the information into a struct which then goes into a linked list. When I close the program it will write to file.
When I open the program with an existing 'record' in the txt (file to be read), add a new record, and print the contents of that new record, It displays information of the initial entry along with the newly added one appended to the end. However, if I were to add another record without closing the program, it is reading the correct information and storing the correct information. I'm puzzled as to why this problem only occurs for the first addition onto an existing list of records.

Problem only occurs when:
1.) There is an existing record to be read from in the txt file
2.) It is the first record to be added on top of the other existing records.

I also found that the data fields that got read wrong were being processed by 'fgets'.

My program is very large. If it is 6 files can I still post it here?

P.S : Works on IDE not on UNIX

If you post 6 files I doubt anybody will be able to read and understand it. Try to reduce your problem to a bare, necessary minimum - you are very likely to find the error yourself when doing that. Also, if you suspect any parts of your program to be the cause of the problems, post them with a description of what you expect them to do. Keep in mind that posting more than 100-200 lines of code is unlikely to be read and/or analyzed by anyone.

Originally Posted by Xirol

If it is 6 files can I still post it here?

Yes, but as kmdv noted the more code you post, the less inclined people will be to read it since they are just volunteering to help for free, so can select to help with whatever appears easier or more interesting.

Originally Posted by Xirol

Well it's a bit complicated since there are so many function calls that lead one to the other, narrowing the code down wouldn't suffice.

That makes it sound like your code is tightly coupled. Have you tried stepping through your code with a debugger?

When you say "Works on IDE not on UNIX", perhaps we could suspect a line ending problem. Are you running on Windows?

I'm running on a MAC. I'll post a portion of the cod

OPTION TO ADD A NEW RECORD

Code:

    int accountno;
    char name[25];
    char address[80];
    int addresscap = 79;
    int yearofbirth;
    char yearinput[10];
    char info[100];
    char filename[] = "data.txt";


           printf("Please create your own account number: ");
            scanf("%s",info);
 
            while(!isInteger(info,99)){
                printf("\nThat is not a valid account number. Only integers are allowed.\n");
                printf("Please create your own account number:");
                scanf("%s",info);
            }
            accountno = atoi(info);
 
            clear(); //removes lingering '\n'
 
            printf("\nPlease enter your name: ");
            fgets(name, 24, stdin);
 
            printf("\nPlease enter your address:\n");
            printf("To finish your input, make a new line after your input and enter 'quit':\n");
            getField(address,addresscap); //Reads multiple lines until user inputs 'quit' 
 
            printf("\nPlease enter your year of birth: ");
            scanf("%s",yearinput);
 
            while(strlen(yearinput) != 4 || !isInteger(yearinput,10)){
                printf("\nNot a valid year of birth. Please try again: \n");
                scanf("%s",yearinput);
            }
            yearofbirth = atoi(yearinput);
 
            addRecord(&start,accountno,name,address,yearofbirth); //Adds into singly linked list

READ FILE CODE

Code:

   FILE *fp = NULL;
    fp = fopen(filename,"r");
 
    int accountno = 0;
    char name[25] = { 0 };
    char address[80] = { 0 };
    int yearofbirth = 0;
    char line[80] = { 0 };
    int opened = 1;
 
    if (fp == NULL){
 
  opened = 1;
 
    } else {
 
  opened = 0;
 
  while (fscanf(fp, "%d\n", &accountno) > 0) {
 
     printf("accountno: %d\n",accountno);
           
     fgets(name, 25, fp);

     while (fgets(line, 80, fp)) {
         if (strcmp(line, "*\n") == 0) {
           strncpy(line,"",sizeof(line)-1);
           break;
          }
          strncat(address, line, 79 - strlen(address));
      }
 
fscanf(fp, "%d", &yearofbirth);
 
            addRecord(start, accountno, name, address, yearofbirth); //Reads each piece of data in the file and adds it to the linked list
 
                strncpy(line,"",sizeof(line)-1); // Used these to try to clear out the array
                strncpy(address,"",sizeof(address)-1);
                strncpy(name,"",sizeof(name)-1);  
        }
    }
 
    if (opened != 1){
    fclose(fp);
    }
 
    return opened;
}

I have made a function that does just that (printing them all), and it comes out nicely except for the FIRST newest addition to a linked list that already has records in it. By print do you mean, my write to file function?

The situation:

1.) Run program with at least one record to be read on the data.txt file
2.) Add a record
3.) Print the record and it contains information from previous data.

INITIAL txt before running program:

1111 //Account number
Person's Name //Name
Their Street //Address
* // Marks the End of Street
1990 // Year of Birth


txt AFTER addition of a record

1111
Person's Name
Their Street
*
1990 //END OF RECORD 1
2222 //START OF RECORD 2
1111 //START of RECORD 2'S NAME (yes this is what is under name)
Person's Name
New Person's Name
Their Street
*
1990 //END
et //START of RECORD 2'S address
*1990
Person's Name
New Person's Name
Their Street
*
1990 //END
1990 // RECORD 2'S year of birth


Its so aggravating.
All my print functions do not alter the information at all. I've tested it because when I add another record after the glitchy one, that prints fine. The only functions that get called throughout this whole process is addRecord/readFile(beginning of program)/and running the option to add a record