Learning C
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C - realloc function
Synopsis:
#include <stdio.h>
void *realloc(void *mem_address, int newsize);
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Description:
The size of the memory block pointed to by the mem_address parameter is changed to the newsize bytes, expanding or reducing the amount of memory available in the block.
In case that mem_address is NULL, the function behaves exactly as malloc, assigning a new block of newsize bytes and returning a pointer to the beginning of it.
In case that the newsize is 0, the memory previously allocated in mem_address is deallocated as if a call to free was made, and a NULL pointer is returned.
Return Value
A pointer to the reallocated memory block, which may be either the same as the mem_address argument or a new location.
Example
#include <stdio.h>
int main ()
{
int input,n;
int count=0;
int * numbers = NULL;
do {
printf ("Enter an integer value (0 to end): ");
scanf ("%d", &input);
count++;
numbers = (int*) realloc (numbers, count * sizeof(int));
if (numbers==NULL)
{ puts ("Error (re)allocating memory"); exit (1); }
numbers[count-1]=input;
} while (input!=0);
printf ("Numbers entered: ");
for (n=0;n<count;n++) printf ("%d ",numbers[n]);
free (numbers);
return 0;
}
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It will proiduce following result:
Enter an integer value (0 to end): 2
Enter an integer value (0 to end): 3
Enter an integer value (0 to end): 4
Enter an integer value (0 to end): 5
Enter an integer value (0 to end): 0
Numbers entered: 2 3 4 5 0
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