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Full Discussion: Declare member of struct as a pointer in c
Top Forums Programming Declare member of struct as a pointer in c Post 302714121 by chap on Thursday 11th of October 2012 08:32:21 PM
Old 10-11-2012
Declare member of struct as a pointer in c
I have a uint8_t *C = malloc(24*sizeof(uint8_t));

I need to send some integers and this *C to another node(in ad hoc network). So I am going to use a struct

Code:
` struct fulMsg { 
int msgType; 
int msgCount; 
//uint8_t *CC;
} fulMsg_t;

typedef struct fulMsg fulMsg_tt;`

there is a method called
Code:
 packetbuf_copyfrom(X, sizeof(X));

in my api(contiki). If I create struct like this
Code:
struct fulMsg *fmsg = &fulMsg_t;

I can use the above method like this
Code:
packetbuf_copyfrom(fmsg, 8);

and from the other end I can easily get those two values.

So my problem is when I am going to apply same thing to that pointer it is not working the network simulator that I am using suddenly be crashed (I think there is a segmentation fault). I can't initialize size of *C in the struct no. And how correctly do this fmsg->CC = C;

At the other end this is how I receive this struct is
Code:
struct fulMsg *r_fmsg = &fulMsg_t;

and
Code:
rfmsg = (fulMsg_tt *)(packetbuf_dataptr());

. So I can easily get values from other end. (No need to do ntoh and hton, but it is ok if this really needs that)

In simple what I want to do is send the value of *C contain and some other integers to another node. How can I correctly do this.

related question post by me regarding this project Segmentation fault when debugging in C
Thanks
 

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LEARN ABOUT SUSE

irsend

IRSEND(1)								FSF								 IRSEND(1)

NAME

       irsend - basic LIRC program to send infra-red commands

SYNOPSIS

       irsend [options] DIRECTIVE REMOTE CODE [CODE...]

DESCRIPTION

       Asks the lircd daemon to send one or more CIR (Consumer Infra-Red) commands. This is intended for remote control of electronic devices such
       as TV boxes, HiFi sets, etc.

       DIRECTIVE can be:
	  SEND_ONCE	    - send CODE [CODE ...] once
	  SEND_START	    - start repeating CODE
	  SEND_STOP	    - stop repeating CODE
	  LIST		    - list configured remote items
	  SET_TRANSMITTERS  - set transmitters NUM [NUM ...]
	  SIMULATE	    - simulate IR event

       REMOTE is the name of a remote, as described in the lircd configuration file.

       CODE is the name of a remote control key of REMOTE, as it appears in the lircd configuration file.

       NUM is the transmitter number of the hardware device.

       For the LIST DIRECTIVE, REMOTE and/or CODE can be empty:

	  LIST	 ""    ""   - list all configured remote names
	  LIST REMOTE  ""   - list all codes of REMOTE
	  LIST REMOTE CODE  - list only CODE of REMOTE

       The SIMULATE command only works if it has been explicitly enabled in lircd.

       -h --help
	      display usage summary

       -v --version
	      display version

       -d --device
	      use given lircd socket [/var/run/lirc/lircd]

       -a --address=host[:port]
	      connect to lircd at this address

       -# --count=n
	      send command n times

EXAMPLES

	  irsend LIST DenonTuner ""
	  irsend SEND_ONCE  DenonTuner PROG-SCAN
	  irsend SEND_ONCE  OnkyoAmpli VOL-UP VOL-UP VOL-UP VOL-UP
	  irsend SEND_START OnkyoAmpli VOL-DOWN ; sleep 3
	  irsend SEND_STOP  OnkyoAmpli VOL-DOWN
	  irsend SET_TRANSMITTERS 1
	  irsend SET_TRANSMITTERS 1 3 4
	  irsend SIMULATE "0000000000000476 00 OK TECHNISAT_ST3004S"

FILES

       /etc/lirc/lircd.conf
	      Default lircd configuration file.  It should contain all the remotes, their infra-red codes and the corresponding timing	and  wave-
	      form details.

DIAGNOSTICS

       If lircd is not running (or /var/run/lirc/lircd lacks write permissions) irsend aborts with the following diagnostics:
       "irsend: could not connect to socket"
       "irsend: Connection refused" (or "Permission denied").

SEE ALSO

       The documentation for lirc is maintained as html pages. They are located under html/ in the documentation directory.

       lircd(8), mode2(1), smode2(1), xmode2(1), irrecord(1), irw(1), http://www.lirc.org.

irsend 0.8.7pre1						     May 2010								 IRSEND(1)
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