Error Reporting

I have a minor problem i want to check for error that the user might enter. For example if i ask for a number and the used enters a letter it would prompt saying that the entered crap here's my code:

Code:

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int emp_details()
{
    FILE *fp;
    fp=fopen("EMP_DETAILS.txt", "a+");

        char emp_name[100];
        char address[100];
        char email[100];
        int tel;
        int age;
        int trn;
        int v_id;

    printf("\n\t\t\t****Employee Information Screen****\n\n\n");


    printf("Enter Employee's Name: ");
    scanf(" %[^\n]s ",&emp_name);
    printf("\n----------------------------------------------------\n");
    printf("\nPlease Enter Employee's Address: ");
    scanf(" %[^\n]s ",&address);
    printf("\n----------------------------------------------------\n");
    printf("\nPlease Enter Employee's Email: ");
    scanf("%s",&email);
    printf("\n----------------------------------------------------\n");
    printf("\nPlease Enter Employee's Telephone #: ");
    scanf("%d",&tel);
    printf("\n----------------------------------------------------\n");
    printf("\nPlease Enter Emplyee's Age: ");
    scanf("%d",&age);
    printf("\n----------------------------------------------------\n");
    printf("\nPlease Enter Employee's TRN#: ");
    scanf("%d",&trn);


            fprintf(fp,"----------------------------------------------------\n");
            fprintf(fp,"Employee Information Generated on: %s", __DATE__);
            fprintf(fp,"\n----------------------------------------------------\n");
            fprintf(fp, "Employee's Name Is: %s\n", emp_name);
            fprintf(fp,"\nEmployee's Address: %s\n", address);
            fprintf(fp,"\nEmployee's Email: %s\n",email);
            fprintf(fp,"\nEmployee's Telephone#: %d\n",tel);
            fprintf(fp,"\nEmployee's Age: %d\n",age);
            fprintf(fp,"\nEmployee's TRN#: %d\n",trn);
            fprintf(fp,"\n----------------------------------------------------\n\n");

    fclose(fp);

    system("CLS");

            printf("\n\n\tInformation Processed... Press Any Key To Return To Main Menu");

    getch();

    system( "CLS");

    first_menu();


}

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Quote:

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Originally Posted by teensicle

I have a minor problem i want to check for error that the user might enter. For example if i ask for a number and the used enters a letter it would prompt saying that the entered crap

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The best idea would be to write a set of functions, one that tries to get a string, one that tries to get a number, etc. Then you can re-use those functions the same way you use scanf() over and over.

Internally, the function could use scanf. scanf()'s return value indicates success and failure. If you want it to grab a number and there is no number to grab, it will return 0.

But you also want to dispose of the incorrect data. So the function should work like this (pseudocode):

Code:

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char *get_a_string () { 
    - first, read a line into a buffer with fgets().
    - apply sscanf to the buffer:
          if we fail, return NULL
          if we succeed, return the string

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You probably want to flesh this out a bit, but that is the general idea -- you absord the input first with fgets, then you "parse" it using sscanf(). Notice, two ss, sscanf(), not scanf(). Look it up ;)

SOMETHING LIKE THIS?

Code:

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printf("Enter Employee's Name: ");
  fflush(stdout);
  if ( fgets(emp_name, sizeof emp_name, stdin) )
  {
      char *newline = strchr(emp_name, '\n'); /* check for trailing '\n' */
      if ( newline )
      {
        *newline =  '\0'; /* overwrite the '\n' with a terminating null */
      }
  }

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