printf a int/float pointer

Hi

I have this function which returns a void pointer:

Code:

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printf( "value is %d\n", (int*)getSomething(input) ) ;
printf( "value is %f\n", (float*)getSomething(input1) ) ;

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This doesn't work because %d and %f do not expect a pointer. So I changed the code to

Code:

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printf( "value is %d\n", *(int*)getSomething(input) ) ;
printf( "value is %f\n", *(float*)getSomething(input1) ) ;

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When I execute the code I get an Bus Error. Why doesn't this work and what is the solution ?

thnx a lot!
Luca

If you want to print the address of the void pointer just print the return value of the function and use %p for formatting.

I need the value

Well, you cannot dereference a void*. What you can do is cast it to an int* for example (if you are trying to get the int value pointed at) and dereference that.

Haven't tried this in a while so I don't remember if it works, but try it out.

Code:

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printf("%d", (*(int*)(something(input))));

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You can't dereference void pointers since they have no size. Change your function to return the type that you are actually returning.

Just tried my code above and it works for me.

it works for me too :)

But, can someone explain the differences between:

Code:

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printf( "value is %d\n", *(int*)getSomething(input) ) ;

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,

Code:

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printf( "value is %d\n", *((int*)getSomething(input)) ) ;

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and

Code:

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printf( "value is %d\n", (*(int*)getSomething(input)) ) ;

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To me, these 3 might all dereference the int value!

Quote:

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Originally Posted by jeanluca

To me, these 3 might all dereference the int value!

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That's because the three are exactly the same....

Thats a good thing (I thought I had Bus errors with the other 2)

thnx!!

Quote:

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Originally Posted by jeanluca

Thats a good thing (I thought I had Bus errors with the other 2)

thnx!!

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Actually, that might very well be a bad thing. Because it probably means you have another unfixed flaw in there now.

EVOEx is correct. Perhaps your problem was in whatever you were doing in that function and not in printing its return value.

I see the 3 running perfectly right now, so the bus error was indeed something else at that time!