On 2006-maj-10, at 17:19, Frank Goenninger wrote:
typedef unsigned long tcflag_t;
typedef unsigned char cc_t;
typedef long speed_t; /* XXX should be unsigned long */
struct termios {
tcflag_t c_iflag; /* input flags */
tcflag_t c_oflag; /* output flags */
tcflag_t c_cflag; /* control flags */
tcflag_t c_lflag; /* local flags */
cc_t c_cc[NCCS]; /* control chars */
speed_t c_ispeed; /* input speed */
speed_t c_ospeed; /* output speed */
};
>
with NCCS being #define'd to 20.
CFFI> (defctype tcflag :unsigned-long)
TCFLAG
CFFI> (defctype cc :unsigned-char)
CC
CFFI> (defctype speed :long)
SPEED
CFFI> (defcstruct termios
(iflag tcflag)
(oflag tcflag)
(cflag tcflag)
(lflag tcflag)
(cc cc :count 20)
(ispeed speed)
(ospeed speed))
TERMIOS
CFFI> (foreign-type-size 'termios)
44
CFFI> (foreign-alloc 'termios)
#.(SB-SYS:INT-SAP #X00600450) ; pointer to 44 newly allocated bytes
CFFI>
I need to allocate space for this struct and therefore want to know
its size ... As I don't need the struct itself I thought about
calculating the size but I figure there's the problem of getting
all the padding to count to the size...
The size depends on the target platform. Different combinations of
CPUs/OSs have different rules for struct alignment and different
sizes for types, so your best bet is to define the struct anyway.
--
Luís Oliveira
http://student.dei.uc.pt/~lmoliv/
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