Thread: Simple Logic problem

I'm having trouble with a small segment of code which should find out wether the number entered is less than or equal to zero. The do while loop asking for employee age wont seem to work. When ever I enter a negative number it accepts it and won't carrying on prompting for a correct age.

Code:

/* Add new employee to database */
static void menu_add_employee(char *line)
{
  new_employee = malloc(sizeof(struct Employee));
  
  fprintf ( stderr, "Enter employee name:\n");
  read_line(stdin, line, MAX_NAME_LENGTH);
  strcpy (new_employee->name, line);
  
  do
  { 
    fprintf ( stderr, "Enter employee sex:\n");
    read_line(stdin, line, 2);
    new_employee->sex = *line;
  } while((line[0] != 'M')&&(line[0] != 'F'));
  
  do
  {
    fprintf ( stderr, "Enter employee age:\n");
    read_line(stdin, line, 4);
    new_employee->age = *line;
  } while((new_employee->age) <= 0); 
  
  fprintf ( stderr, "Enter employee job:\n");
  read_line(stdin, line, MAX_JOB_LENGTH);
  strcpy (new_employee->job, line);

  new_employee->next = NULL;
  if (employee_list_start==NULL) 
     employee_list_start = new_employee; 
  employee_list_end = new_employee;
  
}

Here is the structure definition:

Code:

/* Employee structure */
struct Employee
{
   char name[MAX_NAME_LENGTH+1]; /* name string */
   char sex;                     /* sex identifier, either 'M' or 'F' */
   int  age;                     /* age */
   char job[MAX_JOB_LENGTH+1];   /* job string */
   
   /* pointers to previous and next employee structures in the linked list */
   struct Employee *prev, *next;
};

static struct Employee *employee_list_start = NULL;
static struct Employee *employee_list_end = NULL;

struct Employee *new_employee;

Here is the code for the read_line function :

Code:

/* Read line of characters from file pointer "fp", copying the characters
   into the "line" string, up to a maximum of "max_length" characters, plus
   one for the string termination character '\0'. Reading stops upon
   encountering the end-of-line character '\n', for which '\0' is substituted
   in the string. If the end of file character EOF is reached before the end
   of the line, the failure condition (-1) is returned. If the line is longer
   than the maximum length "max_length" of the string, the extra characters
   are read but ignored. Success is returned (0) on successfully reading
   a line */
static int read_line ( FILE *fp, char *line, int max_length )
{
   int i;
   char ch;

   /* initialize index to string character */
   i = 0;

   /* read to end of line, filling in characters in string up to its
      maximum length, and ignoring the rest, if any */
   for(;;)
   {
      /* read next character */
      ch = fgetc(fp);

      /* check for end of file error */
      if ( ch == EOF )
	    return -1;

      /* check for end of line */
      if ( ch == '\n' )
      {
	   line[i] = '\0';
	   return 0;
      }

      /* fill character in string if it is not already full*/
      if ( i < max_length )
	    line[i++] = ch;
   }

   /* the program should never reach here */
   return -1;
}

Ahh I see, how can I set the age to the whole number and not just the first character?

So you're getting a string and you want the integral representation of the "number" in that string? Search around for the "atoi" function if so.