Date: Wed, 5 Apr 2017 13:23:16 -0300 From: Mario Lobo <lobo@bsd.com.br> To: freebsd-questions@freebsd.org Cc: FreeBSD Hackers <freebsd-hackers@freebsd.org> Subject: [OFF-TOPIC] C question Message-ID: <20170405132251.536ab064@Papi>
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Hi There !
I don't know if this list is appropriate for this.=20
if it isn't, please point me to the right direction.
Since this is for a Freebsd program, I decided to start here, hoping to
find some C gurus who can help me out.
Here it goes:
1) I have this;
typedef struct {
ulong me;
ulong record;
char string[256];
}KFNODE;
KFNODE ***Nodes;
2) Then allocate for the pointers;
Nodes =3D (KFNODE ***) malloc(5 * sizeof(KFNODE **));
memset( Nodes, 0x00, (5 * sizeof(KFNODE **))); =20
for(a =3D 0; a < 5; a++) {
Nodes[a] =3D (KFNODE **) malloc(43 * sizeof(KFNODE *));
memset( Nodes[a], 0x00, (43 * sizeof(KFNODE *)));
}
3) Allocate for the structs
for(a =3D 0; a < 5; a++) {
for(b =3D 0; b < 43; b++) {=20
Nodes[a][b] =3D (KFNODE *) malloc(sizeof(KFNODE));
memset( Nodes[a][b], 0x00, sizeof(KFNODE));
}
}
=46rom this point on, I can access any Nodes[a<5][b<43]. This works fine
as long as I previously know is a 2D array.
My question is: The dimensions are not known before hand and have to be
found at run time.
Suppose I find out I'll need a 3D array, like Nodes[a][b][c]?
How can I dynamically change the level of indirection?
How can I dynamically switch:
----------------
KFNODE ***Nodes; to KFNODE ****Nodes;
----------------
Nodes =3D (KFNODE ***) malloc(5 * sizeof(KFNODE **));
to Nodes =3D (KFNODE ****) malloc(5 * sizeof(KFNODE ***));
----------------
and so forth?
Is this possible at all?
Thanks
--=20
Mario Lobo
http://www.mallavoodoo.com.br
FreeBSD since 2.2.8 [not Pro-Audio.... YET!!]
=20
"UNIX was not designed to stop you from doing stupid things,=20
because that would also stop you from doing clever things."
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