x SuSE Linux 13.1-RELEASE x
x SuSE Linux 13.1-RELEASEx
REALLOCARRAY(3bsd) LOCAL REALLOCARRAY(3bsd)
NAME
reallocarray -- memory allocation and deallocation
LIBRARY
library ``libbsd''
SYNOPSIS
#include <stdlib.h>
(See libbsd(7) for include usage.)
void *
reallocarray(void *ptr, size_t nmemb, size_t size);
DESCRIPTION
When using malloc() be careful to avoid the following idiom:
if ((p = malloc(num * size)) == NULL)
err(1, "malloc");
The multiplication may lead to an integer overflow, which can be avoided
using the extension reallocarray(), as follows:
if ((p = reallocarray(NULL, num, size)) == NULL)
err(1, "malloc");
Alternatively calloc() is a more portable solution which comes with the
cost of clearing memory.
If malloc() must be used, be sure to test for overflow:
if (size && num > SIZE_MAX / size) {
errno = ENOMEM;
err(1, "overflow");
}
The use of reallocarray() or calloc() is strongly encouraged when allo-
cating multiple sized objects in order to avoid possible integer over-
flows.
RETURN VALUES
The reallocarray() function returns a pointer to the allocated space if
successful; otherwise, a null pointer is returned and errno is set to
ENOMEM.
SEE ALSO
malloc(3), calloc(3), alloca(3)
HISTORY
reallocarray() appeared in OpenBSD 5.6, glibc 2.26.
BSD November 14, 2024 BSD
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