brk() - Unix, Linux System Call
Tutorials Point


  Unix for Beginners
  Unix Shell Programming
  Advanced Unix
  Unix Useful References
  Unix Useful Resources
  Selected Reading

Copyright © 2014 by tutorialspoint



  Home     References     Discussion Forums     About TP  

brk() - Unix, Linux System Call


previous next AddThis Social Bookmark Button

Advertisements

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



previous next Printer Friendly

Advertisements


  

Advertisements



Advertisements