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[ubuntu gcc] Returning address of a local variable...


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  #1  
Old December 30th, 2010, 03:14 PM
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[ubuntu gcc] Returning address of a local variable...
Hello friends. What can go wrong if i return the address of a local variable as follows:
Code:
int* fun()
{
int a=10;
return (&a);
}

int main()
{
int *ptr=fun();
return 0;
}
I mean that i have the address of the place. i can use it anyway i want then. isn't it.
Thanks
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Old December 30th, 2010, 05:21 PM
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Its behavior is undefined. Could crash the program, could work. Just don't do it.
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Old December 31st, 2010, 02:32 AM
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The address returned is a location on the stack, although the behaviour undefined, if you take the value immediately after the call, you are likely to get the expected value, however any subsequent function call is likely to be overwritten since the stack space will be reused.

I stress likely because compiler optimisations may affect the actual result. It is just bad and dangerous practice.
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