ALLOCA(3)              FreeBSD Library Functions Manual              ALLOCA(3)

NAME
     alloca - memory allocator

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <stdlib.h>

     void *
     alloca(size_t size);

DESCRIPTION
     The alloca() function allocates size bytes of space in the stack frame of
     the caller.  This temporary space is automatically freed on return.

RETURN VALUES
     The alloca() function returns a pointer to the beginning of the allocated
     space.

SEE ALSO
     brk(2), calloc(3), getpagesize(3), malloc(3), realloc(3)

HISTORY
     The alloca() function appeared in Version 32V AT&T UNIX.

BUGS
     The alloca() function is machine and compiler dependent; its use is
     discouraged.

     The alloca() function is slightly unsafe because it cannot ensure that
     the pointer returned points to a valid and usable block of memory.  The
     allocation made may exceed the bounds of the stack, or even go further
     into other objects in memory, and alloca() cannot determine such an
     error.  Avoid alloca() with large unbounded allocations.

FreeBSD 13.1-RELEASE-p6        September 5, 2006       FreeBSD 13.1-RELEASE-p6