BRK(2) System Calls Manual BRK(2)NAME
brk, sbrk, break - change core allocation
SYNOPSIS
char *brk(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 64
bytes on the PDP11, 256 bytes on the Interdata 8/32, 512 bytes on the VAX-11/780). Locations not less than addr and below the stack
pointer are not in the address space and will thus 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.
When a program begins execution via exec the break is set at the highest location defined by the program and data storage areas. Ordinar-
ily, therefore, only programs with growing data areas need to use break.
SEE ALSO exec(2), malloc(3), end(3)DIAGNOSTICS
Zero is returned if the break could be set; -1 if the program requests more memory than the system limit or if too many segmentation regis-
ters would be required to implement the break.
BUGS
Setting the break in the range 0177701 to 0177777 (on the PDP11) is the same as setting it to zero.
ASSEMBLER
(break = 17.)
sys break; addr
Break performs the function of brk. The name of the routine differs from that in C for historical reasons.
BRK(2)
Check Out this Related Man Page
BRK(2) System Calls Manual BRK(2)NAME
brk, sbrk - change memory allocation
SYNOPSIS
#include <u.h>
#include <libc.h>
int brk(void *addr)
void* sbrk(ulong incr)
DESCRIPTION
Brk sets the system's idea of the lowest bss location not used by the program (called the break) to addr rounded up to the next multiple of
8 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.
When a program begins execution via exec the break is set at the highest location defined by the program and data storage areas. Ordinar-
ily, therefore, only programs with growing data areas need to use brk. A call to sbrk with a zero argument returns the lowest address in
the dynamic segment.
SOURCE
/sys/src/libc/9sys/sbrk.c
SEE ALSO intro(2), malloc(2), segattach(2), segbrk(2)DIAGNOSTICS
These functions set errstr.
The error return from sbrk is (void*)-1.
BRK(2)
Attempting to break from a case/esac paragraph while inside of a function. When executing the code below, entering the letter 'a', will prove that the directory exists, but the break command works for the if/fi, but not for the case/esac. So, in my example below, if an A is entered, the function... (8 Replies)
Does anyone know how to send break on a Blade 100?
I'm using a serial cable on my laptop and I can see the system boot up just fine, but I want to send break so i can have it boot from cdrom instead of disk. (3 Replies)
Hi,
I am having this segmentation fault not in the following program, bt. in my lab program . My lab program is horrible long so cannot post it here bt. I am using the following logic in my program which is giving the segmentation fault. Bt. if I run this sample program as it is it dosen't give... (3 Replies)
Hi,
thanks to a precedent post, and thanks to the reply of derekludwig of the forum, I have convert my first awk command as :
test.txt is : AAAAAGHIJKLAjKMEFJKLjklABCDJkLEFGHIJKL
awk -f findstring.awk test.txt > textreturn.txtfindstring.awk is :
BEGIN{ SLENGTH = 3 }
{
... (3 Replies)