@c ----------------------------------------------------------------------
@node brk, memory
@heading @code{brk}
@subheading Syntax

@example
#include <stdlib.h>

int brk(void *ptr);
@end example

@subheading Description

This function changes the @emph{break} for the program.  This is the
first address that, if referenced, will cause a fault to occur.  The
program asks for more memory by specifying larger values for @var{ptr}. 
Normally, this is done transparently through the @code{malloc} function. 

@subheading Return Value

zero if the break was changed, -1 if not.  @var{errno} is set to the
error. 

@subheading Example

@example
if (brk(old_brk+1000))
  printf("no memory\n");
@end example

