DaniWeb Forum Index > Software Development > C

C RSS

Wats the problem in this Prog???

Thread Solved

•

Join Date: Aug 2008

Posts: 42

Reputation: abhisdm is an unknown quantity at this point

Solved Threads: 4

abhisdm

Offline

Light Poster

Wats the problem in this Prog???

Aug 3rd, 2008

I'm getting an error msg as Type mismatch in redeclaration of 'putw' for the following code... Can anyone suggest the reason for this???

 Help with Code Tags 
 C Syntax (Toggle Plain Text) 
#include<stdio.h>
union pw{
short int i;
char ch[2];
};
int putw(short int num, FILE *fp);
int main()
{
  FILE *fp;
  fp=fopen("test.tmp","wb+");
  putw(1000,fp);
  fclose(fp);
  return 0;
}
int putw(short int num, FILE  *fp)
{
union pw word;
word.i=num;
putc(word.ch[0],fp);
return putc(word.ch[1],fp);
}
#include<stdio.h>
union pw{
short int i;
char ch[2];
};
int putw(short int num, FILE *fp);
int main()
{
  FILE *fp;
  fp=fopen("test.tmp","wb+");
  putw(1000,fp);
  fclose(fp);
  return 0;
}
int putw(short int num, FILE  *fp)
{
union pw word;
word.i=num;
putc(word.ch[0],fp);
return putc(word.ch[1],fp);
}

Last edited by Tekmaven; Aug 4th, 2008 at 6:30 am. Reason: Code tags

•

Join Date: Dec 2006

Posts: 2,028

Reputation: Aia has much to be proud of

Solved Threads: 175

Aia

Offline

Postaholic

Re: Wats the problem in this Prog???

Aug 4th, 2008

Name putw() to something different like putword(). Most likely there's an implementation of putw() already prototyped in your compiler library.

Please, make sure you use proper tags when you post code next time. Here's how.

Last edited by Aia; Aug 4th, 2008 at 12:12 am.

•

Join Date: Aug 2008

Posts: 42

Reputation: abhisdm is an unknown quantity at this point

Solved Threads: 4

abhisdm

Offline

Light Poster

Re: Wats the problem in this Prog???

Aug 4th, 2008

@ AIA
Thanks ....
There existed a function in lib..
But the declaration of function was
int putw(int w, FILE *stream)
the only difference between this and the declaration in prog above is that short int is being used in the putw function...
Does that cause a problem???

•

Join Date: Dec 2006

Posts: 2,028

Reputation: Aia has much to be proud of

Solved Threads: 175

Aia

Offline

Postaholic

Re: Wats the problem in this Prog???

Aug 4th, 2008

>Does that cause a problem???
There can not be two functions named with the same identifier. Even if they both do the same.

Last edited by Aia; Aug 4th, 2008 at 1:08 am.

•

Join Date: Jul 2008

Posts: 2,001

Reputation: ArkM has much to be proud of

Solved Threads: 343

ArkM

Offline

Postaholic

Re: Wats the problem in this Prog???

Aug 4th, 2008

Moreover, visually identical functions with int and short int arguments have different compiled bodies codes and calling codes too. For example, to pass short int arg the compiler emits "push half-word" CPU instruction but for int arg it emits "load word" instruction...