memcpyv()

Arguments:

dst

An array of iovec structures that you want to copy the data to.

dparts

The number of entries in the dst array.

doff

The offset into data represented by the dst array to start copying to.

src

An array of iovec structures that you want to copy the data from.

sparts

The number of entries in the src array.

soff

The offset into data represented by the src array to start copying from.

Library:

libc

Use the -l c option to qcc to link against this library. This library is usually included automatically.

Description:

The memcpyv() function copies data pointed to by the src I/O vector, starting at offset soff, to the dst I/O vector, starting at offset doff. The number of parts in each I/O vector is specified by sparts and dparts.

Returns:

The number of bytes copied.

Examples:

This example copies data from a two-part I/O vector, starting at offset 5, into a three-part vector, starting at offset 3:

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <sys/types.h>
#include <unistd.h>

void print_buffer (char * buffer, char * buffer_name,
                   int buffer_len)
{
        int i;
        
        printf ("   %s: '", buffer_name);
        for (i = 0; i < buffer_len; i++)
        {
                if (buffer[i] == 0)
                  printf ("_");
                else
                  printf ("%c", buffer[i]);
        }
        printf ("'\n");
}
        
int main( void )
{
   char msg1a[10]="1234567890",
        msg1b[20]="abcdefghijklmnop",
        msg2a[10], msg2b[10], msg2c[20];
        
   iov_t dest[3], source[2];
   int dparts=3, sparts=2;
   size_t nbytes, doffset=3, soffset=5;
        
   SETIOV (source + 0, &msg1a, sizeof (msg1a));
   SETIOV (source + 1, &msg1b, sizeof (msg1b));
        
   printf ("Original data:\n");
   print_buffer (msg1a, "msg1a", sizeof (msg1a));
   print_buffer (msg1b, "msg1b", sizeof (msg1b));

   SETIOV (dest + 0, &msg2a, sizeof (msg2a));
   SETIOV (dest + 1, &msg2b, sizeof (msg2b));
   SETIOV (dest + 2, &msg2c, sizeof (msg2c));
   memset (msg2a, 0, sizeof (msg2a));
   memset (msg2b, 0, sizeof (msg2b));
   memset (msg2c, 0, sizeof (msg2c));
   
   nbytes = memcpyv ( dest, dparts, doffset,
                      source, sparts, soffset );
   printf ( "\nCopied %d bytes:\n", nbytes );
   print_buffer (msg2a, "msg2a", sizeof (msg2a));
   print_buffer (msg2b, "msg2b", sizeof (msg2b));
   print_buffer (msg2c, "msg2c", sizeof (msg2c));

   return EXIT_SUCCESS;
}

This program produces the following output:

Original data:
   msg1a: '1234567890'
   msg1b: 'abcdefghijklmnop____'

Copied 25 bytes:
   msg2a: '___67890ab'
   msg2b: 'cdefghijkl'
   msg2c: 'mnop________________'

Classification:

QNX OS