C - Return a null pointer or a pointer to 0 bytes? .....

Return a null pointer or a pointer to 0 bytes? .....

Q

What should malloc(0) do? Return a null pointer or a pointer to 0 bytes?

✍: Guest

A

The ANSI/ISO Standard says that it may do either; the behavior is implementation-defined ortable code must either take care not to call malloc(0), or be prepared for the possibility of a null return.

2016-04-21, 1217👍, 0💬

How can I dynamically allocate arrays?
How can I dynamically allocate arrays? The equivalence between arrays and pointers allows a pointer to malloc'ed memory to simulate an array quite effectively. After executing #include <stdlib.h> int *dynarray; dynarray = malloc(10 * sizeof(int)); (and if the call to malloc succeeds), you can... 2016-04-23, 1294👍, 0💬

malloc is returning crazy pointer values ...
malloc is returning crazy pointer values, I have included the line extern void *malloc(); before I call it. malloc accepts an argument of type size_t, and size_t may be defined as unsigned long. If you are passing ints (or even unsigned ints), malloc may be receiving garbage (or similarly if you are... 2016-04-15, 1271👍, 0💬

I have heard that some operating systems dont actually allocate...
I've heard that some operating systems don't actually allocate malloc'ed memory until the program tries to use it. Is this legal? It's hard to say. The Standard doesn't say that systems can act this way, but it doesn't explicitly say that they can't, either. (Such a ``deferred failure'' implementati... 2016-04-21, 1229👍, 0💬

Return a null pointer or a pointer to 0 bytes? .....
What should malloc(0) do? Return a null pointer or a pointer to 0 bytes? The ANSI/ISO Standard says that it may do either; the behavior is implementation-defined ortable code must either take care not to call malloc(0), or be prepared for the possibility of a null return. 2016-04-21, 1218👍, 0💬

All rights in the contents of this web site are reserved by the individual author. fyicenter.com does not guarantee the truthfulness, accuracy, or reliability of any contents.