How to define an array of struct nested within a struct?

[Daniel Rudy]

Is the following code legal?

typedef stuct data_type_tag {
int var1;
int var2;
int var3;
struct {
void *p;
size_t size;
unsigned int flags;
} ptrs[64];
} data_type_t;


What I am trying to do is something like this:


int c, p;
data_type_t *data;

int main(void)
{
p = 0
data = malloc(sizeof(data_type_t));
for (c = 0; c < MAXSIZE; c++)
{
data->prts[c].size = p;
data->ptrs[c].ptr = NULL;
data->ptrs[c].flags = 0;
}
}


Is that the correct way of building a structure with a format like that?


--
Daniel Rudy

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[Vladimir S. Oka]

Daniel Rudy opined:

typedef stuct data_type_tag {
int var1;
int var2;
int var3;
struct {
void *p;
size_t size;
unsigned int flags;
} ptrs[64];
} data_type_t;


What I am trying to do is something like this:


int c, p;
data_type_t *data;

int main(void)
{
p = 0
data = malloc(sizeof(data_type_t));
for (c = 0; c < MAXSIZE; c++)
{
data->prts[c].size = p;
data->ptrs[c].ptr = NULL;
data->ptrs[c].flags = 0;
}
}

It looks OK. You did re-type instead of copy/paste. Don't do that.

I'd also suggest you define the inner structure outside, and use that
in the declaration of the final one. Much cleaner, and very useful if
you ever need to use it in other places as well.

 

[Daniel Rudy]

At about the time of 3/28/2006 11:04 PM, Vladimir S. Oka stated the
following:

Daniel Rudy opined:

typedef stuct data_type_tag {
int var1;
int var2;
int var3;
struct {
void *p;
size_t size;
unsigned int flags;
} ptrs[64];
} data_type_t;


What I am trying to do is something like this:


int c, p;
data_type_t *data;

int main(void)
{
p = 0
data = malloc(sizeof(data_type_t));
for (c = 0; c < MAXSIZE; c++)
{
data->prts[c].size = p;
data->ptrs[c].ptr = NULL;
data->ptrs[c].flags = 0;
}
}

It looks OK.

Thanks. I wasn't sure how it should look, and none of my reference
materials clearly explained this particular situation.

You did re-type instead of copy/paste. Don't do that.

The code is a simplified example to illustrate what I am trying to do.

I'd also suggest you define the inner structure outside, and use that
in the declaration of the final one. Much cleaner, and very useful if
you ever need to use it in other places as well.

Thanks for looking it over.

--
Daniel Rudy

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[Vladimir S. Oka]

At about the time of 3/28/2006 11:04 PM, Vladimir S. Oka stated the
following:

The code is a simplified example to illustrate what I am trying to do.

Making sure it's syntactically correct makes it easier for someone
who'd like to copy/paste and run the example. It may not have been as
important in this case, but will generally increase the number and
quality of replies to questions.

Thanks for looking it over.

You're welcome.

 

[Captain Winston]

Is the following code legal?

typedef stuct data_type_tag {
int var1;
int var2;
int var3;
struct {
void *p;
size_t size;
unsigned int flags;
} ptrs[64];
} data_type_t;


What I am trying to do is something like this:


int c, p;
data_type_t *data;

int main(void)
{
p = 0

I'am afraid you just have missed a ";".

data = malloc(sizeof(data_type_t));
for (c = 0; c < MAXSIZE; c++)
{
data->prts[c].size = p;
data->ptrs[c].ptr = NULL;
data->ptrs[c].flags = 0;
}

Well, it will be better to add a statement "return 0;".

}


Is that the correct way of building a structure with a format like that?

OK, basically I agree with your method.

 

[John Bode]

Is the following code legal?

typedef stuct data_type_tag {
int var1;
int var2;
int var3;
struct {
void *p;
size_t size;
unsigned int flags;
} ptrs[64];
} data_type_t;

Perfectly legal, although I'd do

struct inner {
void *p;
size_t size;
unsigned int flags;
};

typedef struct data_type_tag {
int var1;
int var2;
int var3;
struct inner ptrs[64];
} data_type_t;

Keeps things a little cleaner.

What I am trying to do is something like this:


int c, p;
data_type_t *data;

int main(void)
{
p = 0
data = malloc(sizeof(data_type_t));

Personally, I'd write that as

data = malloc(sizeof *data);

That way you don't have to worry about syncing the data type with the
item being allocated.

for (c = 0; c < MAXSIZE; c++)
{
data->prts[c].size = p;
data->ptrs[c].ptr = NULL;
data->ptrs[c].flags = 0;
}
}


Is that the correct way of building a structure with a format like that?

Looks okay to me.

 

[kar1107]

Is the following code legal?

typedef stuct data_type_tag {
int var1;
int var2;
int var3;
struct {
void *p;
size_t size;
unsigned int flags;
} ptrs[64];
} data_type_t;


What I am trying to do is something like this:


int c, p;
data_type_t *data;

int main(void)
{
p = 0
data = malloc(sizeof(data_type_t));
for (c = 0; c < MAXSIZE; c++)
{
data->prts[c].size = p;
data->ptrs[c].ptr = NULL;
data->ptrs[c].flags = 0;
}
}

It is legal as long as MAXSIZE < 64.

Karthik

 

[Daniel Rudy]

At about the time of 3/30/2006 9:47 PM, (e-mail address removed) stated the
following:

Is the following code legal?

typedef stuct data_type_tag {
int var1;
int var2;
int var3;
struct {
void *p;
size_t size;
unsigned int flags;
} ptrs[64];
} data_type_t;


What I am trying to do is something like this:


int c, p;
data_type_t *data;

int main(void)
{
p = 0
data = malloc(sizeof(data_type_t));
for (c = 0; c < MAXSIZE; c++)
{
data->prts[c].size = p;
data->ptrs[c].ptr = NULL;
data->ptrs[c].flags = 0;
}
}

It is legal as long as MAXSIZE < 64.

Karthik

Is that the correct way of building a structure with a format like that?

True. Like I said earlier, I wrote this code on the fly as an example.
I was looking for the basic format of how to get it done.

--
Daniel Rudy

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Why geeks like computers: look chat date touch grep make unzip
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