memcpyv()

Copy data from one I/O vector to another

Synopsis:

#include <string.h>

size_t memcpyv( const struct iovec *dst,
                int dparts,
                int doff,
                const struct iovec *src,
                int sparts,
                int soff );

Since:

BlackBerry 10.0.0

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, doffset=3, sparts=2, soffset=5;
   size_t nbytes;
        
   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 4

Safety:  
Cancellation point No
Interrupt handler Yes
Signal handler Yes
Thread Yes

Last modified: 2014-06-24



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