Data structure offset c

What does offset function do in C?
In the C programming language, an offset usually refers to the distance or displacement between the starting memory address of an array and the memory address of a specific element in the array._{Feb 27, 2023}.
What is offset in structure C?
C's offsetof() macro is an ANSI C library feature found in stddef. h.
It evaluates to the offset (in bytes) of a given member within a struct or union type, an expression of type size_t..
What is offset in union in C?
The offsetof() macro is an ANSI -required macro that should be found in stddef. h.
Simply put, the offsetof() macro returns the number of bytes of offset before a particular element of a struct or union.
The declaration of the macro varies from vendor to vendor and depends upon the processor architecture..
The full technique:
1. Get the offset using offsetof: b_offset = offsetof(struct mystruct, member_b);
2. Get the address of your structure as a char * pointer
3. Add the add the offset to the structure address, cast the value to a pointer to the appropriate type and dereference: *(int *)(sc + b_offset)

Sep 11, 2013Use offsetof() to find the offset from the start of z or from the start of x . #include size_t offsetof(type, member);. offsetof() How can I get/set a struct member by offset - Stack OverflowC/C++ Structure offset - Stack OverflowHow to design structure elements in c language by offsetC struct memory layout offsets - Stack OverflowMore results from stackoverflow.com

Sep 11, 2013Use offsetof() to find the offset from the start of z or from the start of x . #include size_t offsetof(type, member);. offsetof() How can I get/set a struct member by offset - Stack OverflowC/C++ Structure offset - Stack OverflowHow to design structure elements in c language by offsetSkip offset in C struct - Stack OverflowMore results from stackoverflow.com

C's offsetof() macro is an ANSI C library feature found in stddef. h. It evaluates to the offset (in bytes) of a given member within a struct or union type, an expression of type size_t.

Does offset of struct A Y & C K work?

@BlueChip Sure it does, you just need to take advantage of the power of your human mind

offsetof (struct a, y) + offsetof (struct c, k) works just fine

It's been 3 years since the question has been asked, I'm adding my answer for the sake of completeness

How do I add an offset to a structure address?

Add the add the offset to the structure address, cast the value to a pointer to the appropriate type and dereference: Ignoring padding and alignment, as you said

If the elements you're pointing to are entirely of a single type, as in your example, you can just cast the structure to the desired type and treat it as an array:

How do I calculate the offset of a struct?

calculate the offset by finding the sizeof the member_a ( int) cast the struct to a single word pointer type ( char ?) create an int pointer and set the address (to *charpointer + offset ?) but I get a bit confused about casting to a char type or if something like memset is more apropriate or if generally i'm aproching this totally wrong

In computing, a data descriptor is a structure containing information that describes data.

Data structure offset c

What does offset function do in C?

What is offset in structure C?

What is offset in union in C?

The full technique:

Does offset of struct A Y & C K work?

How do I add an offset to a structure address?

How do I calculate the offset of a struct?