How to copy array of struct in C

Question

I have defined struct like

typedef struct {
    char *oidkey;
    int showperf;
    char oidrealvalue[BUFSIZE];
    char *oidlimits;
} struct_oidpairs;

and I have array of struct

 struct_oidpairs b[] ={{.....},....}

and I want to copy it to new struct array a[]

please help

Answer 1

Something like this:

memcpy(dest, src, sizeof(struct) * sizeof(src));

Answer 2

maybe using :

for(int i=0; i<b.size() ;i++) 
//I am not sure if this is the correct name for the size function
{
a[i]=b[i];
}

Answer 3

Your struct contains pointers as data members, this means you will have to roll out your own copy function that will do something sensible with the pointers. memcpy only works is all the data related to the struct is stored in the struct.

Answer 4

Makes NOT a deep copy:

struct_oidpairs b[] = {...};
size_t len = sizeof b/sizeof*b;
struct_oidpairs *a = malloc(sizeof b);

if( !a ) /* ERROR handling */

memcpy( a, b, sizeof b );
...
free( a );

or

while( len-- )
  a[len] = b[len];
...
free( a );