Unix/Linux Go Back    


NetBSD 6.1.5 - man page for alloca (netbsd section 3)

Linux & Unix Commands - Search Man Pages
Man Page or Keyword Search:   man
Select Man Page Set:       apropos Keyword Search (sections above)


ALLOCA(3)			   BSD 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.  If the
     allocation failed, a NULL pointer is returned.

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

CAVEATS
     Few limitations can be mentioned:

     o	 The alloca() function is machine dependent; its use is discouraged.

     o	 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.

     o	 Since alloca() modifies the stack at runtime, it causes problems to certain security
	 features.  See security(7) for a discussion.

BSD					  March 21, 2011				      BSD
Unix & Linux Commands & Man Pages : ©2000 - 2018 Unix and Linux Forums


All times are GMT -4. The time now is 01:29 PM.