I think what I am doing is legal, but I am not 100% sure. I have function "A" that sets a pointer from a returned pointer location from function "B".
Also, I thought that a neater method would be if B returned nothing but modified A's pointer's address. Could B malloc some space at a pointer passed to it?Code:void A(void) { char *myvar; myvar = B(); } char *B(void) { char *myvar2; myvar2 = malloc(100); return myvar2; }
If I am unclear, let me know.
What makes you think that it might result in undefined behaviour? At a glance, it looks perfectly fine, except that B() is really only casting the pointer returned by malloc() to char*, and pretty much does nothing else.
Yes, but you would need to pass a pointer to a pointer so that the pointer in A()'s scope can point to the object returned by the malloc() call in B().Originally Posted by carrotcake1029
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That was just an example, obviously I will do more.
So would something like this be what you are talking about for the function to be able to allocate space. I may just avoid this, I think it could get ugly in some cases.
Code:void A(void) { char *myvar; B(&myvar); //Is this a pointer to a pointer, or would i need to do char **myvar? } void B(char **myvar2) { *myvar2 = malloc(100); }
Yes.
It depends. You also should provide a size argument (a pointer too) so that B() can set it, otherwise A() would have no idea how many elements were allocated.
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