NAME

POSIX::1003::Limit - POSIX access to ulimit and rlimit

SYNOPSIS

  # ULIMIT support

  use POSIX::1003::Limit; # load all names

  use POSIX::1003::Limit qw(ulimit);
  # keys are strings!
  $size = ulimit('UL_GETFSIZE');

  use POSIX::1003::Limit qw(ulimit UL_GETFSIZE);
  $size = UL_GETFSIZE;   # constants are subs

  use POSIX::1003::Limit '%ulimit';
  my $key = $ulimit{UL_GETFSIZE};
  $ulimit{_SC_NEW_KEY} = $key_code;
  $size = ulimit($key);

  print "$_\n" for keys %ulimit;

  # RLIMIT support

  use POSIX::1003::Limit ':rlimit';

  my ($cur, $max, $success) = getrlimit('RLIMIT_CORE');
  my ($cur, $max) = getrlimit('RLIMIT_CORE');
  my $cur = RLIMIT_CORE;

  my $success = setrlimit('RLIMIT_CORE', 1e6, 1e8);
  setrlimit('RLIMIT_CORE', 1e6) or die;
  setrlimit('RLIMIT_CORE', RLIM_SAVED_MAX, RLIM_INFINITY);
  RLIMIT_CORE(1e6, 1e8);

DESCRIPTION

This module provides access to the "ulimit" (user limit) and "rlimit" (resource limit) handling. On most systems, ulimit() is succeeded by rlimit() hence provides a very limited set of features.

FUNCTIONS

Standard POSIX

getrlimit(RESOURCE)

  my ($cur, $max, $success) = getrlimit('RLIMIT_CORE');
  my ($cur, $max) = getrlimit('RLIMIT_CORE');

setrlimit(RESOURCE, CUR, [MAX])

  my $success = setrlimit('RLIMIT_CORE', 1e6, 1e8);

ulimit(NAME)

Returns the ulimit value related to the NAMEd constant. The NAME must be a string. undef will be returned when the NAME is not known by the system.

  my $filesize = ulimit('UL_GETFSIZE') || SSIZE_MAX;

Additional

rlimit_names()

Returns a list with all known resource names, unsorted.

ulimit_names()

Returns a list with all known names, unsorted.

CONSTANTS

%ulimit

This exported variable is a tied HASH which maps UL_* names on unique numbers, to be used with ulimit().

%rlimit

This exported variable is a tied HASH which maps RLIMIT_* names on unique numbers, to be used with getrlimit() and setrlimit().

The following constants where detected on your system when the module got installed. The second column shows the value which where returned at that time.

For ulimit, with a value when it is a getter:

  UL_GETFSIZE    9223372036854775807
  UL_GETMAXBRK   undef
  UL_GETOPENMAX  1024
  UL_SETFSIZE    (setter)

The constant names for rlimit, with the soft and hard limits that getrlimit() returned during installation of the module.

  RLIMIT_AS          18446744073709551615, 18446744073709551615
  RLIMIT_CORE        0, 18446744073709551615
  RLIMIT_CPU         18446744073709551615, 18446744073709551615
  RLIMIT_DATA        18446744073709551615, 18446744073709551615
  RLIMIT_FSIZE       18446744073709551615, 18446744073709551615
  RLIMIT_LOCKS       18446744073709551615, 18446744073709551615
  RLIMIT_MEMLOCK     65536, 65536
  RLIMIT_MSGQUEUE    819200, 819200
  RLIMIT_NICE        0, 0
  RLIMIT_NLIMITS     0, 15
  RLIMIT_NOFILE      1024, 4096
  RLIMIT_NPROC       61461, 61461
  RLIMIT_OFILE       1024, 4096
  RLIMIT_RSS         18446744073709551615, 18446744073709551615
  RLIMIT_RTPRIO      0, 0
  RLIMIT_RTTIME      18446744073709551615, 18446744073709551615
  RLIMIT_SIGPENDING  61461, 61461
  RLIMIT_STACK       8388608, 18446744073709551615

SEE ALSO

This module is part of POSIX-1003 distribution version 0.92, built on February 25, 2013. Website: http://perl.overmeer.net. The code is based on POSIX, which is released with Perl itself. See also POSIX::Util for additional functionality.

COPYRIGHTS

Copyrights 2011-2013 on the perl code and the related documentation by [Mark Overmeer]. For other contributors see ChangeLog.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. See http://www.perl.com/perl/misc/Artistic.html