access violation error while trying to memset() the typedef element of the struct

[bamsi]

Hi All,
I have a typedef element defined inside the struct which i am trying to assign value using the memset and strcpy function.I am able to compile but while running it give me access violation error.Here is my code

**********
#ifndef DEFINE_SAMPLETYPES
#define DEFINE_SAMPLETYPES

typedef char MANUFACTURER_PART_NUMBER[48];

#endif

*******************************************
#ifndef DEFINE_SAMPLE_WKSP
#define DEFINE_SAMPLE_WKSP
#include "SAMPLETYPEDEF.H"
typedef struct{

MANUFACTURER_PART_NUMBER manufacturer_part_number;

}IN_SAMPLE_WKSP;

#endif
****************************
#include "SAMPLE_WKSP.H"

 IN_SAMPLE_WKSP *po;

 main()
 {

memset(&(po)->manufacturer_part_number,' ',48);
strcpy(&(po)->manufacturer_part_number,"hello");

}

can you guide me where i am doing mistake.Is this correct way of accessing the typedef element in a struct.

Thanks for the Help

[ashitpro]

Hi All,
I have a typedef element defined inside the struct which i am trying to assign value using the memset and strcpy function.I am able to compile but while running it give me access violation error.Here is my code
**********
#ifndef DEFINE_SAMPLETY PES
#define DEFINE_SAMPLETY PES

typedef char MANUFACTURER_PA RT_NUMBER[48];

#endif

*************** *************** *************
#ifndef DEFINE_SAMPLE_W KSP
#define DEFINE_SAMPLE_W KSP
#include "SAMPLETYPEDEF. H"
typedef struct{

MANUFACTURER_PA RT_NUMBER manufacturer_pa rt_number;

}IN_SAMPLE_WKSP ;

#endif
*************** *************
#include "SAMPLE_WKS P.H"

IN_SAMPLE_WKSP *po;

main()
{

memset(&(po)->manufacturer_p art_number,' ',48);
strcpy(&(po)->manufacturer_p art_number,"hel lo");

}

can you guide me where i am doing mistake.Is this correct way of accessing the typedef element in a struct.

Thanks for the Help

According to my knowledge,
you ll have to first allocate the memory to IN_SAMPLE_WKSP *po;
then do your memset and other logic.

[donbock]

Another way to put it is that po is an uninitialized pointer. You need to initialize it to point at an IN_SAMPLE_WKSP.

[Banfa]

memset(&(po)->manufacturer_part_number,' ',48);
strcpy(&(po)->manufacturer_part_number,"hello");

Even if you initialise po correctly these lines are not correct the & is unnecessary. This effects the type, rather than the value, of the pointer but most good compilers would issue a warning for this.