Do While Loop Failing when compiled w/ GCC but not on Windows Dev-C++

[erinod]

Hi all,

The following program successfully applies the do while loop when the user enters 'Y' or 'y' when run in Windows after being compiled with Dev C++. That is what my Intro to Algorithms class uses. But when I take the same code and compile it on linux with gcc, it doesn't respond properly to y or Y, and ends the program. Here's the code:

#include  <stdio.h> // reqd for printf(), scanf() and fprintf()
#include <string.h>
#define addr(var) &var
#define REPORTHEADINGS "     Name                   Pay Rate     Hours     Gross     Tax     Net\n"
#define FORMAT         "     %-23s%8.2f%10.2f%10.2f%8.2f%10.2f\n"
#define TAXRATE 0.15

	
  int main(void)
    {
      char lastName[15+1];
      char firstName[13+1];
      char fullName[15+13+2+1];
      float payrate,hours,gross;
      float tax;
      float netpay;
      char answer;
	
      FILE * reportFile;
       
      reportFile = fopen("/home/erin/Documents/IntroAlgorithms/file.txt","wt");               
      fprintf(reportFile,REPORTHEADINGS);
       printf(REPORTHEADINGS); 
	    
      do {
		printf("Enter employee's last name: ");  
		scanf("%s",lastName);
		printf("Enter employee's first name: "); 
		scanf("%s",firstName);
		printf("Enter hourly pay rate: ");
		scanf("%f",addr(payrate));
		printf("Enter hours worked this pay period: ");
		scanf("%f",addr(hours));
		
		if (hours <= 40)
	           gross = hours * payrate;
	        else
                   gross = 40 * payrate + (hours-40)*1.5*payrate;   
                   tax = gross * TAXRATE;
                   netpay = gross-tax;    
          
		strcpy(fullName,lastName);
		strcat(fullName,", ");
		strcat(fullName,firstName);
		printf(FORMAT,fullName,payrate,hours,gross,tax,netpay);
	      
		fprintf(reportFile,FORMAT,fullName,payrate,hours,gross,tax,netpay);
		fflush(stdin); // clear keyboard buffer before answer input
		printf("Another employee(Y/N) ");
		scanf("%c",addr(answer));
		} 
	while (answer == 'Y' || answer == 'y');
		
	    
      fclose(reportFile);
      fflush(stdin);
      getchar();
      return 0;
    }

Any advice would be awesome. Thanks!

[alf55]

I see two things that are not "standard C" code.

• The "t" in the mode within the fopen call
• fflush flushes output buffers and not input buffers.

According to the C Standard:

int fflush(FILE* stream);

Flushes stream stream and returns zero on success or EOF on error.

Effect undefined for input stream. fflush(NULL) flushes all output streams.