Ytukyg

I'm working on a program that records students grades. The user inputs first name, last name, student ID, grade, and assignment name. I'm supposed to have the input from the user separated by being tabbed rather than a space. But when I execute the program the output in the txt file isn't correct.

#include <stdio.h>



int main(void){



   FILE *cfPtr; // cfPtr = clients.txt file pointer



// fopen opens file. Exit program if unable to create file

if ((cfPtr = fopen("grades.txt", "w")) == NULL) {

    puts("File could not be opened.");

} 

else {

    puts("Enter the students first & last name, ID, grade, and assignment.");



    puts("Enter EOF to end input.");

    printf("%s", "? ");



    char firstName[30]; // student first name

    char lastName[30]; // student last name

    unsigned int stuID; // student ID

    double grade; // student grade

    char assignment[10]; // student assignment name



    scanf("%5s%5s%d%lf%5s", firstName, lastName, &stuID, &grade, assignment);



    // write first & last name, student ID, grade, and assignment name into file with fprintf



    while(!feof(stdin)) {

        fprintf(cfPtr, "%st%st%dt%.2ft%stn", firstName, lastName, stuID, grade, assignment);

        fflush(cfPtr);

        printf("%s", "? ");

        scanf("%5s%5s%d%lf%5s", firstName, lastName, &stuID, &grade, assignment);

    } // end while



    fclose(cfPtr); // fclose closes file

   } // end else

} // end main

Heres what happens when I execute it:

Enter the students first & last name, ID, grade, and assignment.

Enter EOF to end input.

? Freddy Krueger 1234 22.33 test1

? ? Jason Vorhees 1235 33.00 test1

? ? The Hulk 1236 2.95 test1

? Bat Man 1237 100.00 test1

? ^Z

[1]+ Stopped ./seqw

grade.txt file output:

Fredd y 0 0.00 ttime

Krueg er 1234 22.33 test1

Jason Vorhe 1234 22.33 test1

es 1235 33 0.00 test1

The Hulk 1236 2.95 test1

Bat Man 1237 100.00 test1

What am I doing wrong here? And where did ttime come from? And it's strange how it's tabbing part of the last name and making it another input.

the following proposed code:

1. cleanly compiles


2. performs the desired functionality


3. properly checks for errors


4. eliminates the 'magic' numbers by using #define statements to give those magic numbers meaningful names


5. The call scanf() could be modified to incorporate the MAX CHARACTERS modifier(s) to be part of the parameter list, rather than hardcoded into the format string

And now, the proposed code:

#include <stdio.h>

#include <stdlib.h>   // exit(), EXIT_FAILURE



#define MAX_FIRSTNAME_LEN 30

#define MAX_LASTNAME_LEN  30

#define MAX_ASSIGNMENT_LEN 10





int main( void )

{

    FILE *cfPtr; // cfPtr = clients.txt file pointer



    // fopen opens file. Exit program if unable to create file

    if ((cfPtr = fopen("grades.txt", "w")) == NULL) 

    {

        perror( "fopen to read grades.txt failed" );

        exit( EXIT_FAILURE );

    } 

    // implied else, fopen successful



    puts("Enter the students first & last name, ID, grade, and assignment.");

    puts("Enter EOF to end input.");

    printf( "%s", "? " );



    char firstName[ MAX_FIRSTNAME_LEN ]; // student first name

    char lastName[ MAX_LASTNAME_LEN ]; // student last name

    unsigned int stuID; // student ID

    double grade; // student grade

    char assignment[ MAX_ASSIGNMENT_LEN ]; // student assignment name



    while( scanf( "%29s %29s %u %lf %9s", firstName, lastName, &stuID, &grade, assignment) == 5 )

    {

        fprintf( cfPtr, 

                 "%st%st%dt%.2ft%stn", 

                 firstName, 

                 lastName, 

                 stuID, 

                 grade, 

                 assignment);

        printf( "%s", "? " );

    } // end while



    fclose( cfPtr ); // fclose closes file

} // end main