offset
sizeof type | structure.field [...] -o structure.field [...] [-w outfile]
Display size of data types in bytes. Additionally display offsets for members of structs. OPTIONS: type | structure.field [...] Print size of types (basic types, structs, typedefs) or member of structures in bytes. -o structure.field [...] Determine the member offset. Only arguments of the form 'structure.field' are allowed. To request size for multi-worded types (e.g. "short int") specify the type within "". Note: An alias "offset" exists for the calling sequence "sizeof -o".
Example 4-13. sizeof
>> sizeof task_struct module_ref int double Size of "task_struct": 1152 bytes Size of "module_ref": 12 bytes Size of "int": 4 bytes Size of "double": 8 bytes >> sizeof mem_map_t page pgd_t Size of "mem_map_t": 40 bytes Size of "page": 40 bytes Size of "pgd_t": 4 bytes >> sizeof page.next mem_map_t.index thread_struct.trace -o Offset: 0 bytes. Offset: 8 bytes. Offset: 100 bytes. >> sizeof "long long unsigned int" "short int" "long double" Size of "long long unsigned int": 8 bytes Size of "short int": 2 bytes Size of "long double": 12 bytes >> sizeof "short unsigned int" mm_struct.count task_struct -o ERROR: Could not determine offset for short unsigned int. Offset: 16 bytes. ERROR: Could not determine offset for task_struct.