error in my code but don't know where!

[laura22]

static char *my_kstrdup(const char *buf)
{
char *ptr, *ret;

ret = ptr = kmalloc(strlen(buf));
if(ptr = NULL)
panic("kmalloc returned NULL");

for(; *buf != '\0'; ++ptr, ++buf)
*ptr = *buf;

*ptr = '\0';

return ret;
}

static char *my_toupper(char *c)
{
if(c >= 'a' && c <= 'z')
return c - 'a' + 'A';
return c;
}

void complex_hello(void)
{
const char *msg = "hello World!!!";
char *copy;

copy = *my_kstrdup(msg);

/* Capitalize the first letter 'Hello World!!!'*/
copy[0] = *my_toupper(copy[0]);


kprintf("%c\n", copy);


}

 

[cpjust]

ret = ptr = kmalloc(strlen(buf));

should be:

ret = ptr = kmalloc(strlen(buf) + 1);

This function might have problems on certain platforms:

static char *my_toupper(char *c)

 

[Salem]

Not to mention
> if(ptr = NULL)
should be == here.


--

 

[SimonSellick]

And are you allowed to ++buf when buf is declared as const?

 

[Salem]

> And are you allowed to ++buf when buf is declared as const?
Yes, because in this context the thing which is const is the thing which is being pointed at.

buf++ is ok, the pointer is being incremented.
(*buf)++ is not, because what buff points to is being incremented.

Declaring either
[tt]const char * const buf
char * const buf[/tt]
on the other hand would prevent buf++

--

 

[SimonSellick]

Ah. Thanks for the clarification