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#include <stdint.h> // for uint8_t
#include <stdio.h> // for printf()
#include <stdlib.h> // for EXIT_SUCCESS
#include <string.h> // for memcpy()
/*---------------------------------------------------------------------------*/
// PROTOTYPES
/*---------------------------------------------------------------------------*/
void * memcpy_safer ( void * destination, size_t sizeOfDestination,
const void * source, size_t sizeOfSource,
size_t num );
void * memcpy_safer2 ( void * destination, size_t sizeOfDestination,
const void * source, size_t sizeOfSource,
size_t num );
void initializeBuffer (void *dataPtr, size_t dataSize, uint8_t value);
void dumpBuffer (const char* prefix, void *dataPtr, size_t dataSize);
/*---------------------------------------------------------------------------*/
// MAIN
/*---------------------------------------------------------------------------*/
int main()
{
uint8_t smallerBuffer[10];
uint8_t largerBuffer[15];
// Test 1: copy longer buffer into smaller buffer.
printf ("\nInitialized buffers:\n\n");
// Initialize buffers with something we can identify later.
initializeBuffer (smallerBuffer, sizeof(smallerBuffer), 0x1);
dumpBuffer ("smallerBuffer", smallerBuffer, sizeof(smallerBuffer));
initializeBuffer (largerBuffer, sizeof(largerBuffer), 0x2);
dumpBuffer ("largerBuffer ", largerBuffer, sizeof(largerBuffer));
printf ("\nTest 1: Copying largerBuffer into smallerBuffer...\n\n");
memcpy_safer (smallerBuffer, sizeof(smallerBuffer), largerBuffer, sizeof(largerBuffer), 42);
// TODO: Also test with a smaller value.
dumpBuffer ("smallerBuffer", smallerBuffer, sizeof(smallerBuffer));
// Test 2: copy smaller buffer into larger buffer.
printf ("\nInitialized buffers:\n\n");
// Initialize buffers with something we can identify later.
initializeBuffer (smallerBuffer, sizeof(smallerBuffer), 0x1);
dumpBuffer ("smallerBuffer", smallerBuffer, sizeof(smallerBuffer));
initializeBuffer (largerBuffer, sizeof(largerBuffer), 0x2);
dumpBuffer ("largerBuffer ", largerBuffer, sizeof(largerBuffer));
printf ("\nTest 2: Copying smallerBuffer into largerBuffer...\n\n");
memcpy_safer (largerBuffer, sizeof(largerBuffer), smallerBuffer, sizeof(smallerBuffer), 42);
// TODO: Also test with a smaller value.
dumpBuffer ("largerBuffer ", largerBuffer, sizeof(largerBuffer));
return EXIT_SUCCESS;
}
/*---------------------------------------------------------------------------*/
// FUNCTIONS
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
// My ridiculous "safer" memcpy.
/*---------------------------------------------------------------------------*/
void * memcpy_safer ( void * destination, size_t sizeOfDestination,
const void * source, size_t sizeOfSource,
size_t num )
{
// Use whichever size is the smallest.
if ((num > sizeOfDestination) || (num > sizeOfSource))
{
if (sizeOfDestination < sizeOfSource)
{
num = sizeOfDestination;
}
else
{
num = sizeOfSource;
}
}
return memcpy ( destination, source, num);
}
/*---------------------------------------------------------------------------*/
// Bing CoPilot changes.
/*---------------------------------------------------------------------------*/
void * memcpy_safer2 ( void * destination, size_t sizeOfDestination,
const void * source, size_t sizeOfSource,
size_t num )
{
if (!destination || !source) {
fprintf(stderr, "Error: NULL pointer passed to memcpy_safer.\n");
return NULL;
}
if (num > sizeOfDestination || num > sizeOfSource) {
size_t adjusted = (sizeOfDestination < sizeOfSource) ? sizeOfDestination : sizeOfSource;
fprintf(stderr, "Warning: Truncating copy from %zu to %zu bytes.\n", num, adjusted);
num = adjusted;
}
return memcpy(destination, source, num);
}
/*---------------------------------------------------------------------------*/
// Utility function to initialize a buffer to a set value.
/*---------------------------------------------------------------------------*/
void initializeBuffer (void *dataPtr, size_t dataSize, uint8_t value)
{
if (NULL != dataPtr)
{
memset (dataPtr, value, dataSize);
}
}
/*---------------------------------------------------------------------------*/
// Utility function to dump bytes in a buffer, with an optional prefix.
/*---------------------------------------------------------------------------*/
void dumpBuffer (const char* prefix, void *dataPtr, size_t dataSize)
{
if (NULL != dataPtr)
{
if (NULL != prefix)
{
printf ("%s: ", prefix);
}
for (size_t idx=0; idx<dataSize; idx++)
{
printf ("%02x ", ((uint8_t*)dataPtr)[idx]);
}
printf ("\n");
}
}
// End of memcpy_safer.c
