malloc problem

[mynicks]

I would like some help for the following code. The output should be: hovercraft
but i get: Xovercraft instead.

I do not know if i messed up my code::blocks settings or simply i fail to spot the mistake :P

#include <iostream>
#include <stdlib.h>
#include <cstring>

using namespace std;

void stringcopy(char *s1, char *s2);

int main()
{
    int statusupdate;
    char s[]="hovercraft";

    char *ptr;
    ptr =(char*) malloc(strlen(s)+1);// if i do not use (char*)
                                             // my compiler says:
 //error: cannot convert 'void (*)(char*, char*)' to 'const char*' 
//for argument '1' to 'size_t strlen(const char*)'|
    
    if(ptr==0)
        statusupdate=1;
    else
    {
        stringcopy(ptr,s);
        cout << ptr;
        free(ptr);
        statusupdate=0;
    }
    return statusupdate;
}
void stringcopy(char *destination, char *source)
{
    int i=0;
    while(source[i++])
        destination[i]=source[i];
    destination[i]='\0';
}

Thanks...

[Little Captain]

It actually has to do with your while loop:

while(source[i++]) //The increment is throwing your loop off 

That will increment the value of i once its done testing it, and so when you finally copy an element, you're starting at source[1] instead of source[0].

I recommend moving the increment to the bottom of the loop instead; should make your code clearer and more easy to debug.

Hope that helps :)

[mynicks]

Thanks for the recommendations.

"code clearer and more easy to debug." I suppose you mean that i should use better names for variables, more spaces on each line .... etc ?

[mutexe]

I suppose you mean that i should use better names for variables, more spaces on each line .... etc ?

Little Captain was suggesting not doing this all on one line:
while(source[i++])

so when debugging it's easier to see the value of i before getting to the while condition test.

e.g.

  
 int i=0;
 while(source[i])  // <-- easier to see/debug what i is in the condition
{
        destination[i]=source[i];
        i++;
}
 destination[i]='\0';