BRK(2) BRK(2)
NAME
brk, sbrk - change core allocation
SYNOPSIS
int brk(addr)
char *addr;
char *sbrk(incr)
DESCRIPTION
Brk sets the system's idea of the lowest location not used
by the program (called the break) to addr rounded up to the
next multiple of 1024 bytes. Locations not less than addr
and below the stack pointer may cause a memory violation if
accessed.
In the alternate function sbrk, incr more bytes are added to
the program's data space and a pointer to the start of the
new area is returned. Rounding occurs as with brk, but a
nominal break is remembered, so rounding does not accumu-
late.
When a program begins execution via exec the break is set at
the highest location defined by the program and data storage
areas. Ordinarily, therefore, only programs with growing
data areas need to use brk.
The error return from sbrk is (char *)-1.
SEE ALSO
exec(2), end(3), malloc(3)
DIAGNOSTICS
ENOMEM