ALLOCA(3)                BSD Library Functions Manual                ALLOCA(3)

NAME
     alloca -- memory allocator

SYNOPSIS
     #include <alloca.h>
     or
     #include <stdlib.h>

     void *
     alloca(size_t size);

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

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

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

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

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

     alloca() 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.

     The use of C99 variable-length arrays and alloca() in the same function
     will cause the lifetime of alloca's storage to be limited to the block
     containing the alloca()

BSD                            September 5, 2006                           BSD