redhat man page for sbrk

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

Linux 0.99.11							    1993-07-21								    BRK(2)