another c simple question

if13121 · #1 20-Oct-2004, 04:37

Dear All, I don't know how to make the function
SetFile in this program work without change it become

CPP / C++ / C Code:

void SetFile(Tab * T, IdxType i,kata v)
 {
    kata x;
    CopyKata(v,&x);
    T->TFile[i] = x;
 }

Anybody pls explain more why the SetFile not work.
When should i pass parameter to function by value or by reference?
why both
void CopyKata ( kata Tin , kata *Tout) and
void CopyKata ( kata *Tin , kata *Tout) work.
Acctually this program derived from several file i just cut some funtion from them. Please just ignore that i just assign many variable with zero. here is the program

CPP / C++ / C Code:

 typedef int IdxType;
  typedef struct {
        char TKata[20];
        int len;
  }kata;

  typedef struct
  {
        int DD;
        int MM;
        int YYYY;
  }date;
   typedef struct
  {
        int  TSize[99];
        date TDate[99];
        kata TFile[99];
        int NBFile;
  }  Tab;

void PrintTable(Tab T);
int  NbElmt(Tab T);
void SetFile(Tab *T, IdxType i,kata v);
void CopyKata ( kata  Tin , kata * Tout);
void getLen(kata *L);

int main()
{
        date L;
        Tab T;
        kata Input,v,w;
        T.TDate[0].DD   = 0;    T.TDate[0].MM   = 0;    T.TDate[0].YYYY = 0;
        T.TDate[1].DD   = 0;    T.TDate[1].MM   = 0;    T.TDate[1].YYYY = 0;
        Input.TKata[0] = 't';   Input.TKata[1] = '.';   Input.TKata[2] = 't';
        Input.TKata[3] = 'x';   Input.TKata[4] = 't';   Input.len = 5;
        T.TSize[0]=1;   T.TSize[1]=1;
        T.NBFile = 2;
        CopyKata(Input,&(T.TFile[0]));
	printf("Add New File to table of content\n");
	printf("Input new file name : \n");
        scanf("%s",v.TKata);
        getLen(&v);
        CopyKata(v,&(T.TFile[1]));
        PrintTable(T);
	printf("Input new file name: \n"); 
        scanf("%s",w.TKata);
        getLen(&w);
        T.TDate[2].DD   = 0; T.TDate[2].MM   = 0; T.TDate[2].YYYY = 0;
        SetFile(&T,2,w);
        T.NBFile = 3;
        T.TSize[2]=3;
        PrintTable(T);
        return 0;
}

void PrintTable(Tab T)
 {
    int i,j;
    printf("\nTable of Content\n");
   
    if (NbElmt(T) != 0 )
    {
    for (i = 0; i < NbElmt(T);i++)
      {
         
         for (j = 0; j < T.TFile[i].len ;j++)
         {
         printf("%c",T.TFile[i].TKata[j]);
         }
        
         printf("   %d",T.TSize[i]);
        
         printf("   %d-"  ,T.TDate[i].DD);
         printf("%d-"  ,T.TDate[i].MM);
         printf("%d\n" ,T.TDate[i].YYYY);
      }
    }
    else 
    {printf("There is no file in mydir\n");}
  }

int NbElmt(Tab T)
{
     return(T.NBFile);
}

void CopyKata ( kata  Tin , kata *Tout)
{
        int i;
        (*Tout).len = (Tin).len;
        for (i = 0; i < Tin.len ;i++)
        {
           (*Tout).TKata[i] = (Tin).TKata[i];
        }

}

 void SetFile(Tab * T, IdxType i,kata v)
 {
        CopyKata(v,T.TFile[i]);
 }

void getLen(kata * L)
{
        int i=0;
        while((*L).TKata[i] != '\0')
        {i++;}
        (*L).len = i;
}

nkhambal · #2 20-Oct-2004, 13:27

It wont work becuase, your CopyKata() expect "Tout" argument as a pointer to the varibale of type kata. So you need to pass "address of TFile[i] in (*T) as &((*T).TFile[i])" and not "T.TFile[i]" where in you are passing start address of structre T.

Sorry, if that doesn't explain it well.

Anyway,changing your SetFile() to the one below will work.

CPP / C++ / C Code:

 void SetFile(Tab *T, IdxType i,kata v)
 {
        
		CopyKata(v,&((*T).TFile[i]));
 }

Also, in Copykata() instead of copying single characters at a time using for loop, you can simply use string copy function strcpy() as below.(Unless there is a specific reason for it to do that way).

CPP / C++ / C Code:

void CopyKata ( kata  Tin , kata * Tout)
{
           
		strcpy((*Tout).TKata,Tin.TKata);
}

Same in PrintTable(). you can change it to

CPP / C++ / C Code:

void PrintTable(Tab T)
 {
    int i,j;
    printf("\nTable of Content\n");
   
    if (NbElmt(T) != 0 )
    {
    for (i = 0; i < NbElmt(T);i++)
      {
         
         printf("%10s\t",T.TFile[i].TKata);
         printf("%d\t",T.TSize[i]);
        
         printf("   %d-"  ,T.TDate[i].DD);
         printf("%d-"  ,T.TDate[i].MM);
         printf("%d\n" ,T.TDate[i].YYYY);
      }
    }
    else 
    {printf("There is no file in mydir\n");}
  }

When I complied and executed the code with these changes, I got following output

CPP / C++ / C Code:

TFile[0].TKata: t.txt
Add New File to table of content
Input new file name : 
n1

Table of Content
     t.txt      1    0-0-0
        n1      1    0-0-0
Input new file name: 
n2

Table of Content
     t.txt      1    0-0-0
        n1      1    0-0-0
        n2      3    0-0-0

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search
Rate This Thread
Rate This Thread:

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
very simple c question	if13121	C Programming Language	1	18-Oct-2004 00:12
New to this forum...just a little question...	rune hunter	C++ Forum	4	16-Oct-2004 09:33
question of practice	magiccreative	C++ Forum	1	06-Feb-2004 07:17
Simple Question regarding installing Apache 2.0	macjoubert	Apache Web Server Forum	0	13-Nov-2003 11:39