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From: Canaan Kao <canaan.kao@gmail.com>
To: ajhwb@knac.com
Cc: linux-c-programming@vger.kernel.org
Subject: Re: Socket programming
Date: Sun, 22 Mar 2009 21:00:14 +0800	[thread overview]
Message-ID: <160bbd1a0903220600g5b93ddaau32e160c856bb77e6@mail.gmail.com> (raw)
In-Reply-To: <20090322054220.1C330C2D@resin14.mta.everyone.net>

Dear Ardhan,

You can add a mySize data member in struct foo.

struct foo
 {
  unsigned mySize;
  char *name;
  char *pix;
  int id;
 };


 struct foo *bar = malloc (sizeof(struct foo));

 if(NULL!=bar)bar->mySize=sizeof(struct foo);

 /* fill the structure, then send */

Finally, your receiver will get the size of foo in the beginning of the stream.

Best regards,
Canaan

On Sun, Mar 22, 2009 at 8:42 PM, Ardhan Madras <ajhwb@knac.com> wrote:
> Hi All,
>
> I was written small network utility in Linux 2.6, glibc 2.7.
> I have been using send() and recv() system call in SOCK_STREAM
> to send or receive fixed size data. for example, i write my data
> structure like this:
>
> struct foo
> {
>  char name[16];
>  char pix[1024];
>  int id;
> } bar;
>
> If i want to send or receive data i just call
>
> send (socket, &bar, sizeof(struct foo), 0);
>
> or to receive:
> recv (socket, &bar, sizeof(struct foo), 0);
>
> My problem is how to receive dynamic sized data? for
> example this structure:
>
> struct foo
> {
>  char *name;
>  char *pix;
>  int id;
> }
>
> struct foo *bar = malloc (sizeof(struct foo));
> /* fill the structure, then send */
>
> How to receive the data? since there are no way
> to the receiver to know data sizes?
>
> Thanks for your help.
>
>
> _____________________________________________________________
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  reply	other threads:[~2009-03-22 13:00 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-03-22 12:42 Socket programming Ardhan Madras
2009-03-22 13:00 ` Canaan Kao [this message]
2009-03-22 18:39 ` Jon Mayo
2009-03-26 21:58   ` Anil Vishnoi
2009-03-23  9:18 ` Glynn Clements
  -- strict thread matches above, loose matches on Subject: below --
2009-03-22 13:31 Ardhan Madras
2009-03-22 13:41 ` Volker Kokula
2009-03-22 15:24 ` Canaan Kao
2009-03-26 21:42   ` Anil Vishnoi
2009-03-22 14:08 Ardhan Madras
2009-03-22 15:04 ` Volker Kokula
2009-03-22 15:47 Ardhan Madras
2009-03-23 15:03 Ardhan Madras

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