NAME    [Toc]    [Back]

       brk, sbrk - change data segment size

SYNOPSIS    [Toc]    [Back]

       #include <unistd.h>

       int brk(void *end_data_segment);

       void *sbrk(ptrdiff_t increment);

DESCRIPTION    [Toc]    [Back]

       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    [Toc]    [Back]

       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    [Toc]    [Back]

       BSD 4.3

       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).

SEE ALSO    [Toc]    [Back]

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



Linux 0.99.11			  1993-07-21				BRK(2)