Thread: Compiler error :

Error is this :


1>e:\documents\visual studio 2005\projects\ozumsafaoglu\ozumsafaoglu\ozumsafaog lu.cpp(15) : error C2440: 'initializing' : cannot convert from 'void *' to 'char *'
1> Conversion from 'void*' to pointer to non-'void' requires an explicit cast

15th line is this :

char *a=malloc(50*sizeof(char));

What is the problem about the casting?

Also in the same program :

Code:

// ozumsafaoglu.cpp : Defines the entry point for the console application.
//

#include "stdio.h"
#include "stdafx.h"
#include "stdlib.h"
int _tmain(int argc, _TCHAR* argv[])
{
	struct section {
		char first[30];
		char second[30];
		int secno;
	};
	int totalline=0; // To find the total section number //
	 char a[40]; // To take each line of the txt to find the total section number //
	FILE *fp;
	if((fp=fopen("liste.txt","r"))==NULL) {
		perror("liste.txt");
	}
	else {
		while((fgets(a,sizeof(a)-1,fp))!=NULL)
		{
			totalline+=1;
		}
        struct section sections[(totalline+1)/3]; // in order to provide minimum memory spent //
		rewind(fp);
       int i=0; // will be in for loop in order to control line number 
	   for(i=0;i<totalline;i++) {
			
			if( i &#37; 3==0) {
				sections[i].secno= i/3 + 1;
				fgets(sections[i/3+1].first,29,fp);
				fgets(sections[i/3+1].second,29,fp);
			    fgets(a,sizeof(a)-1,fp);
			}
	   }

	   for(i=0;i<totalline;i++) {
		   printf("section %d\n",sections[i].secno);
		   printf("%s\n%s\n\n",sections[i].first,sections[i].second);
	   }
	
	
	
	}







	
	return 0;
}

Error messages :

1>------ Build started: Project: ozumsafaoglu, Configuration: Debug Win32 ------
1>Compiling...
1>ozumsafaoglu.cpp
1>e:\documents\visual studio 2005\projects\ozumsafaoglu\ozumsafaoglu\ozumsafaog lu.cpp(17) : warning C4996: 'fopen' was declared deprecated
1> d:\program files\microsoft visual studio 8\vc\include\stdio.h(234) : see declaration of 'fopen'
1> Message: 'This function or variable may be unsafe. Consider using fopen_s instead. To disable deprecation, use _CRT_SECURE_NO_DEPRECATE. See online help for details.'
1>e:\documents\visual studio 2005\projects\ozumsafaoglu\ozumsafaoglu\ozumsafaog lu.cpp(26) : error C2057: expected constant expression
1>e:\documents\visual studio 2005\projects\ozumsafaoglu\ozumsafaoglu\ozumsafaog lu.cpp(26) : error C2466: cannot allocate an array of constant size 0
1>e:\documents\visual studio 2005\projects\ozumsafaoglu\ozumsafaoglu\ozumsafaog lu.cpp(26) : error C2133: 'sections' : unknown size
1>Build log was saved at "file://e:\Documents\Visual Studio 2005\Projects\ozumsafaoglu\ozumsafaoglu\Debug\Buil dLog.htm"
1>ozumsafaoglu - 3 error(s), 1 warning(s)
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========



-----------------------------
The aim of my program :

There is a text file :

Tuesday 15:40 17:30 F19
Thursday 15:40 17:30 F17

Tuesday 15:40 17:30 FZ19
Thursday 12:40 14:30 F19

Tuesday 15:40 17:30 F15
Thursday 12:40 14:30 FZ19

Monday 10:40 12:30 F19
Thursday 12:40 14:30 F15

My program takes each pairs of line in individual sturct variables. That moduler of 3 is used for this aim.Than I will assign section number to each of them and print them on the screen with section numbers. I am trying to achive taking them into struct successfully.

I have made a this kind of change :

Code:

FILE *fp;
	FILE **fpt;
	
	fpt=&fp;
	if((fopen_s(fpt,"liste.txt","r"))==NULL) {
		perror("liste.txt");
	}

Errors became this:
1>------ Build started: Project: ozumsafaoglu, Configuration: Debug Win32 ------
1>Compiling...
1>ozumsafaoglu.cpp
1>e:\documents\visual studio 2005\projects\ozumsafaoglu\ozumsafaoglu\ozumsafaog lu.cpp(29) : error C2057: expected constant expression
1>e:\documents\visual studio 2005\projects\ozumsafaoglu\ozumsafaoglu\ozumsafaog lu.cpp(29) : error C2466: cannot allocate an array of constant size 0
1>e:\documents\visual studio 2005\projects\ozumsafaoglu\ozumsafaoglu\ozumsafaog lu.cpp(29) : error C2133: 'sections' : unknown size
1>Build log was saved at "file://e:\Documents\Visual Studio 2005\Projects\ozumsafaoglu\ozumsafaoglu\Debug\Buil dLog.htm"
1>ozumsafaoglu - 3 error(s), 0 warning(s)
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========


It is interesting though. So my fopen function is not secure , is it like reaching the file pointer after reaching the other FILE pointer(**) which points to it?

No I heard you. But visual c++ is capable of compiling c codes. stdafx contains the stdio library. Doesnt it ?

I simply had a look at the inside of stdafx. There was #include stdio.h . But I added the second include anyway. It compiles any program but this.

I have tried a differemnt program. COmpiler did not give error. But program gave failure. I will give you the soruce code , so you can decide this is because of compiler or me.

Code:

#include "stdafx.h"
#include "stdio.h"
#include "string.h"

int _tmain(int argc, _TCHAR* argv[])
{
	char *araba[3];
	int i=0;
	for(i=0;i<3;i++) araba[i]=NULL;
	char x[6]="naber";
	
	strcpy_s(araba[0],5*sizeof(char),x);
	printf("%s",araba[0]);
	return 0;
}

It's because of you.
Kurt

Wait , what the hell is kurt? If you are meaning the race , that is ugly and unrelated with me. If you did not mean this , I am sorry .
But why did you say because of you and went away. Why didnt you at least try to express it .

Originally Posted by ozumsafa

But why did you say because of you and went away. Why didnt you at least try to express it .

You didn't ask.
This time it sounds a litle more like a question.

Code:

strcpy_s(araba[0],5*sizeof(char),x);

araba[0] doesn't point anywhere useful.
Kurt -- That's my name ( not my fault )

When using malloc(), you need to #include <stdlib.h> (in C - if you are writing C++, #include <cstdlib> or better yet use new() instead). That should eliminate the casting warning.

I am sorry for my post kurt. I rreally forgot to put & there , but isnt tht araba[0] already pointer.?

(About kurt , I didnt guess you would put your name under your message)

Shure it's a pointer but you have initialized it to point to null. You cannot copy anything to that location.
Kurt