Need help on my code.

This is a discussion on Need help on my code. within the C Programming forums, part of the General Programming Boards category; I run it with my compiler and the code crashed without any error. Anything wrong with this code? Please help ...

  1. #1
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    Question Need help on my code.

    I run it with my compiler and the code crashed without any error. Anything wrong with this code? Please help me out. Thank you guys.

    Code:
    /*
     * A sample program to read-from and write-to files. Also shows how to
     * send a file as a parameter and display error messages to standard
     * error.
     */
    
    #include "test.h"
    #include <stdio.h>
    #include <stdlib.h>
    #include <string.h>
    #include <conio.h>
    
    
    
    
    int
    main ( void )
    {
       void rmNl ( char s[] );
       int lineWithBlanks ( char *s );
       FILE *fin, *fout;
       STUDENT stuArr[MAX_STUDENTS];
       int numItems = 0; // counter to keep track of items processed
       int i, FinalGrade;
       
       /* Open file to read input data */
       if ( ( fin = fopen ( "input.dat", "r" ) ) == NULL ) {
          fprintf ( stderr, "Could not open file input.dat\n" );
       }
       else {
          for(i=1;i<=MAX_STUDENTS;i++)   
          fscanf(fin,"%s%s\n%d\n%d%d%d%d%d\n%d%d%d\n",stuArr[i].fName,stuArr[i].lName,&stuArr[i].id,stuArr[i].hw[0],&stuArr[i].hw[1], &stuArr[i].hw[2],&stuArr[i].hw[3], &stuArr[i].hw[4],&stuArr[i].exm[0],&stuArr[i].exm[1],&stuArr[i].exm[2]);
    
       }
       fclose(fin);
       
       /* Open file for writing output */
       if ( ( fout = fopen ( "output.dat", "w" ) ) == NULL ) {
          fprintf ( stderr, "Could not open file output.dat\n" );
       }
       else {
        fprintf(fout, "%s\n", "==============================================");
        fprintf(fout, "%s\n", "              PRINTING ALL RECORDS            ");
        fprintf(fout, "%s\n", "==============================================");
        fprintf(fout, "%-10s%-10s%-8s%-8s%-8s%s\n","Student","Name","Id","HAvg","EAvg","Grade"); 
        
           while (!feof(fin))   {
                 
              fprintf( fout,"%-10s%-10s%-8d%-8.2f%-8.2f",stuArr[i].fName,stuArr[i].lName,&stuArr[i].id,stuArr[i].hwAvg,&stuArr[i].exmAvg);
          
              stuArr[i].hwAvg = (stuArr[i].hw[0] + stuArr[i].hw[1] + stuArr[i].hw[2] + stuArr[i].hw[3] + stuArr[i].hw [4]) / 5;
              stuArr[i].exmAvg = (stuArr[i].exm[0] + stuArr[i].exm[1] +  stuArr[i].exm[2]) / 3;
              FinalGrade = (stuArr[i].hwAvg * 0.4) + (stuArr[i].exmAvg * 0.6);
       
              if (FinalGrade >= 85 && FinalGrade <= 100.00) stuArr[i].grade = 'A';
                 else if (FinalGrade >= 75 && FinalGrade <= 84) stuArr[i].grade = 'B';
                 else if (FinalGrade >= 60 && FinalGrade <= 74) stuArr[i].grade = 'C';
                 else if (FinalGrade >= 50 && FinalGrade <= 59) stuArr[i].grade = 'D';
                 else if (FinalGrade < 50) stuArr[i].grade == 'F';
              fprintf( fout,"%c\n", stuArr[i].grade);
           }
       }   
    
       fclose(fout);    
       return 0;
    }

  2. #2
    Devil's Advocate SlyMaelstrom's Avatar
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    MAX_STUDENTS isn't declared. Show your struct, also you should try compiling a .c not a .cpp cause that's not a valid struct declaration.
    Sent from my iPad®

  3. #3
    Sr. Software Engineer filker0's Avatar
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    Your loop goes from 1 to MAX_STUDENTS, C arrays are indexed from 0 through the number of elements - 1. As a result, you're accessing beyond the end of your array.

    I can't swear this is why the program errors out, but it's a start.
    Insert obnoxious but pithy remark here

  4. #4
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    I put the structure in test.h which code is being posted below. I put .c for the file. I'll try to fix the problem u said, filker0.

    Code:
    #define NAME_LEN 30
    #define NUM_HW 5 
    #define NUM_EXM 3
    #define MAX_STUDENTS 80
    #define BUFLEN  80
    
    typedef struct STUDENT
       {
          char fName[NAME_LEN];
          char lName[NAME_LEN];
          int id;
          int hw[NUM_HW];
          int exm[NUM_EXM];
          float hwAvg;
          float exmAvg;
          char grade;
       } STUDENT;

  5. #5
    Devil's Advocate SlyMaelstrom's Avatar
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    Get rid of the STUDENT before the last semicolon, and what filker0 said was the problem is correct. It's also what I imagined would be it.

    You can't be compiling this as a C file because you aren't declaring an object correctly.

    Code:
    struct foo {};
    
    int main() {
      struct foo one;  // Is C legal
      foo two;         // Not C legal
    
      return 0;
    }
    Sent from my iPad®

  6. #6
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    After I carefully editted and examined my code, I still have some warning and error in my code such as:

    grades.c:12:19: conio.h: No such file or directory
    grades.c: In function `main':
    grades.c:36: warning: format argument is not a pointer (arg 6)
    grades.c:58: warning: int format, pointer arg (arg 5)
    grades.c:58: warning: double format, pointer arg (arg 7)
    grades.c:73:32: missing terminating " character
    grades.c:74: error: syntax error before "exists"
    grades.c:74: error: stray '\' in program
    grades.c:74:9: missing terminating " character
    grades.c:69: warning: statement with no effect

    Please help me out on those errors and warnings, and here is my code:

    grades.c
    Code:
    
    #include "grades.h"
    #include <stdio.h>
    #include <stdlib.h>
    #include <string.h>
    #include <conio.h>
    
    
    
    
    int
    main ( void )
    {
       FILE *fin, *fout;
       STUDENT stuArr[MAX_STUDENTS];
       int i = 0, FinalGrade;
       
       /* Open file to read input data */
       if ( ( fin = fopen ( "grades.in", "r" ) ) == NULL ) {
          fprintf ( stderr, "Could not open file grades.in\n" );
          fclose (fin);
          exit ( -1 );
       }
       else {
               
          while (i < MAX_STUDENTS) {   
          fscanf(fin,"%s%s\n%d\n%d%d%d%d%d\n%d%d%d\n",stuArr[i].fName,stuArr[i].lName,&stuArr[i].id,stuArr[i].hw[0],&stuArr[i].hw[1], &stuArr[i].hw[2],&stuArr[i].hw[3], &stuArr[i].hw[4],&stuArr[i].exm[0],&stuArr[i].exm[1],&stuArr[i].exm[2]);
          fclose (fin);
          }
       }
       
       /* Open file for writing output */
       if ( ( fout = fopen ( "grades.out", "w" ) ) == NULL ) {
          fprintf ( stderr, "Could not open file grades.out\n" );
          fclose ( fout);
          exit ( -1 );
       }
       else {
    
    
          fprintf(fout, "%s\n", "==============================================");
          fprintf(fout, "%s\n", "              PRINTING ALL RECORDS            ");
          fprintf(fout, "%s\n", "==============================================");
          fprintf(fout, "%-10s%-10s%-8s%-8s%-8s%s\n","Student","Name","Id","HAvg","EAvg","Grade"); 
        
          while (!feof(fin))  {  
              if (strcmp(stuArr[0].fName,stuArr[1].fName)!= 0) {  
                 fprintf( fout,"%-10s%-10s%-8d%-8.2f%-8.2f",stuArr[i].fName,stuArr[i].lName,&stuArr[i].id,stuArr[i].hwAvg,&stuArr[i].exmAvg);
          
                 stuArr[i].hwAvg = (stuArr[i].hw[0] + stuArr[i].hw[1] + stuArr[i].hw[2] + stuArr[i].hw[3] + stuArr[i].hw [4]) / 5;
                 stuArr[i].exmAvg = (stuArr[i].exm[0] + stuArr[i].exm[1] +  stuArr[i].exm[2]) / 3;
                 FinalGrade = (stuArr[i].hwAvg * 0.4) + (stuArr[i].exmAvg * 0.6);
       
                    if (FinalGrade >= 85 && FinalGrade <= 100.00) stuArr[i].grade = 'A';
                    else if (FinalGrade >= 75 && FinalGrade <= 84) stuArr[i].grade = 'B';
                    else if (FinalGrade >= 60 && FinalGrade <= 74) stuArr[i].grade = 'C';
                    else if (FinalGrade >= 50 && FinalGrade <= 59) stuArr[i].grade = 'D';
                    else if (FinalGrade < 50) stuArr[i].grade == 'F';
                    fprintf( fout,"%c\n", stuArr[i].grade);
              }
              else {
                 fprintf ( stderr, "Could not add entry of %s%s_ErrorInAcct with id: %d - id already exists\n", stuArr[i].fName, stuArr[i].lName, stuArr[i].id);
                 fprintf ( stderr, "Incorrect number of entries for the name field of %s_ErrorInAcct", stuArr[i].fName);
                 fprintf ( stderr, "Incorrect number of entries for id field of %s_ErrorInAcct", stuArr[i].fName);
                 fprintf ( stderr, "Incorrect number of entries for homework field of %s_ErrorInAcct", stuArr[i].fName);
                 fprintf ( stderr, "Incorrect number of entries for exam field of %s_ErrorInAcct", stuArr[i].fName);        
              }   
           }
       fclose (fout);
       }
    return 0;
    }
    grades.h
    Code:
    #define NAME_LEN 30
    #define NUM_HW 5 
    #define NUM_EXM 3
    #define MAX_STUDENTS 80
    
    typedef struct STUDENT
       {
          char fName[NAME_LEN];
          char lName[NAME_LEN];
          int id;
          int hw[NUM_HW];
          int exm[NUM_EXM];
          float hwAvg;
          float exmAvg;
          char grade;
       }STUDENT;

  7. #7
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    140
    The warnings tell you exactly where to go....

    remove #include <conio.h> it's not standard and you do not use it at all.

    Missing an &
    Code:
    fscanf(fin,"%s%s\n%d\n%d%d%d%d%d\n%d%d%d\n",stuArr[i].fName,stuArr[i].lName,&stuArr[i].id,&stuArr[i].hw[0],&stuArr[i].hw[1], &stuArr[i].hw[2],&stuArr[i].hw[3], &stuArr[i].hw[4],&stuArr[i].exm[0],&stuArr[i].exm[1],&stuArr[i].exm[2]);
    Remove the 2 &s
    Code:
    fprintf( fout,"%-10s%-10s%-8d%-8.2f%-8.2f",stuArr[i].fName,stuArr[i].lName,&stuArr[i].id,stuArr[i].hwAvg,&stuArr[i].exmAvg);
    Should be = not ==
    Code:
    else if (FinalGrade < 50) stuArr[i].grade == 'F';

  8. #8
    ATH0 quzah's Avatar
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    Quote Originally Posted by SlyMaelstrom
    Get rid of the STUDENT before the last semicolon, and what filker0 said was the problem is correct. It's also what I imagined would be it.

    You can't be compiling this as a C file because you aren't declaring an object correctly.

    Code:
    struct foo {};
    
    int main() {
      struct foo one;  // Is C legal
      foo two;         // Not C legal
    
      return 0;
    }
    It's a typedef. While it's not a good idea to use the same name like they did, it is C. Consider:
    Code:
    typedef struct foo { ... } bar;
    We have defined that 'bar' is in essence an alias for 'struct foo'. Thus, we can now do:
    Code:
    struct foo x; /* x is an instance of struct foo */
    bar y; /* y is an instance of bar, which is really a 'struct foo' */

    Quzah.
    Hope is the first step on the road to disappointment.

  9. #9
    Devil's Advocate SlyMaelstrom's Avatar
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    Hmm... I see.
    Sent from my iPad®

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