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realloc_ptr.c
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realloc_ptr.c
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#include "shs.h"
/**
* _realloc - Reallocates a memory block.
*
* @ptr: Pointer to the memory previously allocated.
* @old_size: Size, in bytes, of the allocated space of ptr.
* @new_size: New size, in bytes, of the new memory block.
*
* Return: Pointer to the reallocated memory block.
* If new_size == old_size, returns ptr without changes.
* If malloc fails, returns NULL.
*/
void *_realloc(void *ptr, unsigned int old_size, unsigned int new_size)
{
void *newptr;
if (!ptr)
return (malloc(new_size));
if (new_size == 0)
{
free(ptr);
return (NULL);
}
if (new_size == old_size)
return (ptr);
newptr = malloc(new_size);
if (!newptr)
return (NULL);
_memcpy(newptr, ptr, (new_size < old_size) ? new_size : old_size);
free(ptr);
return (newptr);
}
/**
* _realloc_ptr - Reallocates a memory block of a double pointer.
*
* @ptr: Double pointer to the memory previously allocated.
* @old_size: Size, in bytes, of the allocated space of ptr.
* @new_size: New size, in bytes, of the new memory block.
*
* Return: Pointer to the reallocated memory block.
* If new_size == old_size, returns ptr without changes.
* If malloc fails, returns NULL.
*/
char **_realloc_ptr(char **ptr, unsigned int old_size, unsigned int new_size)
{
char **newptr;
unsigned int i;
if (!ptr)
return (malloc(sizeof(char *) * new_size));
if (new_size == old_size)
return (ptr);
newptr = malloc(sizeof(char *) * new_size);
if (!newptr)
return (NULL);
for (i = 0; i < old_size; i++)
newptr[i] = ptr[i];
free(ptr);
return (newptr);
}
/**
* _memcpy - Copies information between void pointers.
*
* @dest: Destination pointer.
* @src: Source pointer.
* @size: Size of the new pointer.
*
* Return: No return value.
*/
void _memcpy(void *dest, const void *src, unsigned int size)
{
char *char_dest = (char *)dest;
const char *char_src = (const char *)src;
unsigned int i;
for (i = 0; i < size; i++)
char_dest[i] = char_src[i];
}