Problem with strncpy

[osfreak]

#include<iostream>
using namespace std;
 
typedef struct mystruct {
 
    unsigned char uDirFlag;
 
    unsigned int uFileSize;
 
    char uFilename[255];
} teststruct;
 
 
int main()
{
    char *flatbuf;
 
    teststruct *a = (teststruct*)malloc(sizeof(teststruct));
 
    a->uDirFlag = '0';
    a->uFileSize = 55;
 
    strcpy(a->uFilename,"Test message");
 
    int k = sizeof(teststruct);
 
    flatbuf = (char*)malloc(k);
 
    memset(flatbuf,0,k);
 
    strncpy(flatbuf, (char *)a, k);       //strncpy fails to copy uFilename properly
 
    teststruct *b = (teststruct*)flatbuf;      // b has uFilename field all set to 0
 
    return 0;
 
}
 
 

b has its uFilename field set to 0.

Can anyone Pls explain me why the the character values in the struct(uFilenam e field) were not copied properly??

[newb16]

Becase unsigned int uFileSize has at least two bytes, and all except least significant are zero, and strncpy stops on it.

[osfreak]

Is there a way i can force strncpy to copy till the specified bytes?

or is there any other string copy function to do such an operation?

[osfreak]

I have got it working by using memcpy(),

If there is someother way pls let me know...

Thanks for your help :)

[JosAH]

@osfreak
You aren't copying a string so don't use any str* function. Use memcpy() or memmove() instead.

kind regards,

Jos

[osfreak]

Got it working... Thanks anyway...