Question

I need clarification for the following notation in C:

I have a struct, and within that struct I have the following field:

bool (* process_builtin)(struct esh_command *);

I am pretty confused here.. So this is a boolean field.. What exactly is process_builtin? I already have a struct esh_command defined, but I have no clue where this plays in this field. Can someone please explain the whole thing’s meaning?

Answer 1

That’s not a boolean field, that’s a pointer to a function taking a struct esh_command* and returning a bool; the field is called process_builtin.

You could also write:

typedef bool (* process_builtin_t)(struct esh_command *);

in which case process_builtin_t would be a type and in which case you could write the definition of that struct member as:

process_builtin_t process_builtin;