BRK(2)                     Linux Programmer's Manual                    BRK(2)
NAME
       brk, sbrk - change data segment size

SYNOPSIS
       #include <unistd.h>

       int brk(void *end_data_segment);

       void *sbrk(intptr_t increment);

DESCRIPTION
       brk()  sets  the  end  of  the  data  segment to the value specified by
       end_data_segment, when that value is reasonable, the system  does  have
       enough  memory  and  the process does not exceed its max data size (see
       setrlimit(2)).

       sbrk() increments the program's data space by increment bytes.   sbrk()
       isn't  a  system  call, it is just a C library wrapper.  Calling sbrk()
       with an increment of 0 can be used to find the current location of  the
       program break.

RETURN VALUE
       On  success,  brk()  returns  zero, and sbrk() returns a pointer to the
       start of the new area.  On error, -1 is returned, and errno is  set  to
       ENOMEM.

CONFORMING TO
       4.3BSD; SUSv1, marked LEGACY in SUSv2, removed in POSIX.1-2001.

       brk() and sbrk() are not defined in the C Standard and are deliberately
       excluded from  the  POSIX.1  standard  (see  paragraphs  B.1.1.1.3  and
       B.8.3.3).

NOTES
       Various  systems use various types for the parameter of sbrk().  Common
       are int, ssize_t, ptrdiff_t, intptr_t.

SEE ALSO
       execve(2), getrlimit(2), malloc(3)

Linux 2.4                         2003-11-01                            BRK(2)