Quota extension module for Perl
-------------------------------
Author: Tom Zoerner (tomzo AT users.sourceforge.net)
Version: 1.7.0
Date: August 2013
DLSIP-Code:Rcdfg
- stable release
- C compiler required for installation
- support by developer
- plain functions, no references used
- licensed under the Perl Artistic License or
(at your option) version 2 or later of the
GNU General Public License
Location: http://www.perl.com/CPAN/authors/Tom_Zoerner/
Supported: SunOS 4.1.3,
Solaris 2.4 - 2.10,
HP-UX 9.0x & 10.10 & 10.20 & 11.00,
IRIX 5.2 & 5.3 & 6.2 - 6.5,
OSF/1 & Digital Unix 4,
BSDi 2, FreeBSD 3.x - 4.9, OpenBSD & NetBSD (no RPC),
Linux - kernel 2.0.30 and later, incl. Quota API v2 and XFS,
AIX 4.1, 4.2 and 5.3.
AFS (Andrew File System) on many of the above (see INSTALL),
VxFS (Veritas File System) on Solaris 2.
Documentation is in pod format at the end of Quota.pm,
installation hints are in a file named INSTALL inside this package.
See also CHANGES for a history of updates to this module.
-----------------------------------------------------------------------------
THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR
IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
-----------------------------------------------------------------------------
NAME
Quota - Perl interface to file system quotas
SYNOPSIS
use Quota;
($block_curr, $block_soft, $block_hard, $block_timelimit,
$inode_curr, $inode_soft, $inode_hard, $inode_timelimit) =
Quota::query($dev [,$uid [,kind]]);
($block_curr, $block_soft, $block_hard, $block_timelimit,
$inode_curr, $inode_soft, $inode_hard, $inode_timelimit) =
Quota::rpcquery($host, $path [,$uid]);
Quota::rpcpeer([$port [,$use_tcp [,timeout]]]);
Quota::setqlim($dev, $uid, $block_soft, $block_hard,
$inode_soft, $inode_hard [,$tlo [,kind]]);
Quota::sync([$dev]);
$arg = Quota::getqcarg([$path]);
Quota::setmntent();
($dev, $path, $type, $opts) = Quota::getmntent();
Quota::endmntent();
DESCRIPTION
The Quota module provides access to file system quotas. The
quotactl system call or ioctl is used to query or set quotas
on the local host, or queries are submitted via RPC to a
remote host. Mount tables can be parsed with getmntent and
paths can be translated to device files (or whatever the
actual quotactl implementations needs as argument) of the
according file system.
Functions
($bc,$bs,$bh,$bt, $ic,$is,$ih,$it) = Quota::query($dev, $uid, $kind)
Get current usage and quota limits for a given file
system and user. The user is specified by its numeric
uid; defaults to the process' real uid.
The type of $dev varies from system to system. It's the
argument which is used by the quotactl implementation to
address a specific file system. It may be the path of a
device file (e.g. /dev/sd0a) or the path of the mount
point or the quotas file at the top of the file system
(e.g. /home.stand/quotas). However you do not have to
worry about that; use Quota::getqcarg to automatically
translate any path inside a file system to the required
$dev argument.
$dev may also be in the form of hostname:path, which has
the module transparently query the given host via a
remote procedure call (RPC). In case you have NFS (or
similar network mounts), this type of argument may also
be produced by Quota::getqcarg. Note: RPC queries
require rquotad(1m) to be running on the target system.
If the daemon or host are down, the timeout is 12
seconds.
In $bc and $ic the current usage in blocks and inodes is
returned. $bs and $is are the soft limits, $bh and $ih
hard limits. If the soft limit is exceeded, writes by
this user will fail for blocks or inodes after $bt or
$it is reached. These times are expressed as usual, i.e.
in elapsed seconds since 00:00 1/Jan/1970 GMT.
Note: When the quota limits are not exceeded, the timestamps
are meaningless and should be ignored. When hard and soft
limits are zero, there is no limit for that user. On most
systems Quota::query will return undef in that case and
errno will be set to ESRCH.
When $kind is given and set to 1, $uid is taken as gid
and group quotas are queried. This is not supported across
RPC and even locally only on a few architectures (e.g. Linux
and other BSD based Unix variants, OSF/1 and AIX - check the
quotactl(2) man page on your systems). When $kind is set
to 2, project quotas are queried; this is currently only
supported for XFS. When unsupported, this flag is ignored.
Quota::setqlim($dev, $uid, $bs,$bh, $is,$ih, $tlo, $kind)
Sets quota limits for the given user. Meanings of $dev,
$uid, $bs, $bh, $is and $ih are the same as in
Quota::query.
For file systems exceeding 2 TB: To allow passing block or
inode values larger or equal to 2^32 on 32-bit Perl versions,
pass them either as strings or floating point.
$tlo decides how the time limits are initialized: 0:
The time limits are set to NOT STARTED, i.e. the time
limits are not initialized until the first write attempt
by this user. This is the default. 1: The time limits
are set to 7.0 days. More alternatives (i.e. setting a
specific time) aren't available in most implementations.
When $kind is given and set to 1, $uid is taken as gid
and group quota limits are set. This is supported only on a
few architectures (see above). When I<$kind> is set to 2,
project quotas are modified; this is currently only supported
for XFS. When unsupported, this flag is ignored.
Note: if you want to set the quota of a particular user
to zero, i.e. no write permission, you must not set all
limits to zero, since that is equivalent to unlimited
access. Instead set only the hard limit to 0 and the
soft limit for example to 1.
Note that you cannot set quotas via RPC.
Quota::sync($dev)
Have the kernel update the quota file on disk or all
quota files if no argument given (the latter doesn't
work on all systems, in particular on HP-UX 10.10).
The main purpose of this function is to check if quota
is enabled in the kernel and for a particular file
system. Read the quotaon(1m) man page on how to enable
quotas on a file system.
Note: on some systems this function always returns a
success indication, even on partitions which do not
have quotas enabled (e.g. Linux). This is not a bug
in this module; it's a limitation in certain kernels.
($bc,$bs,$bh,$bt, $ic,$is,$ih,$it) =
Quota::rpcquery($host,$path,$uid)
This is equivalent to Quota::query("$host:$path",$uid),
i.e. query quota for a given user on a given remote
host via RPC. $path is the path of any file or
directory inside the wanted file system on the remote
host.
Quota::rpcpeer($port,$use_tcp,timeout)
Configure parameters for subsequent RPC queries; all
parameters are optional. By default the portmapper on
the remote host is used (i.e. default port is 0,
protocol is UDP) The default timeout is 4 seconds.
Quota::rpcauth($uid,$gid,$hostname)
Configure authorization parameters for subsequent
RPC queries; all parameters are optional. By default
uid and gid are taken from owner of the process and
hostname is the host name of current machine.
$arg = Quota::getqcarg($path)
Get the required $dev argument for Quota::query and
Quota::setqlim for the file system you want to operate
on. $path is any path of an existing file or directory
inside that file system. The path argument is optional
and defaults to the current working directory.
The type of $dev varies between operating systems, i.e.
different implementations of the quotactl functionality.
Hence it's important for compatibility to always use
this module function and not really pass a device file
to Quota::query (as returned by Quota::getdev). See
also above at Quota::query
$dev = Quota::getdev($path)
Returns the device entry in the mount table for a
particular file system, specified by any path of an
existing file or directory inside it. $path defaults to
the working directory. This device entry need not really
be a device. For example on network mounts (NFS) it's
"host:mountpath", with amd(1m) it may be something
completely different.
NEVER use this to produce a $dev argument for other
functions of this module, since it's not compatible. On
some systems quotactl does not work on devices but on
the quotas file or some other kind of argument. Always
use Quota::getqcarg.
Quota::setmntent()
Opens or resets the mount table. This is required before
the first invocation of Quota::getmntent.
Note: on some systems there is no equivalent function in
the C library. But you still have to call this module
procedure for initialization of module-internal
variables.
($dev, $path, $type, $opts) = Quota::getmntent()
Returns the next entry in the system mount table. This
table contains information about all currently mounted
(local or remote) file systems. The format and location
of this table (e.g. /etc/mtab) vary from system to
system. This function is provided as a compatible way to
parse it. (On some systems, like OSF/1, this table isn't
accessible as a file at all, i.e. only via
Quota::getmntent).
Quota::endmntent()
Close the mount table. Should be called after the last
use of Quota::getmntent to free possibly allocated file
handles and memory. Always returns undef.
Quota::strerr()
Translates $! to a quota-specific error text. You should
always use this function to output error messages, since
the normal messages don't always make sense for quota
errors (e.g. ESRCH: No such process, here: No quota for
this user)
Note that this function only returns a defined result if
you called a Quota command directly before which returned
an error indication.
RETURN VALUES
Functions that are supposed return lists or scalars, return
undef upon errors. As usual $! contains the error code (see
Quota::strerr).
Quota::endmntent always returns undef. All other functions
return 0 upon success, non-zero integer otherwise.
EXAMPLES
An example for each function can be found in the test script
test.pl. See also the contrib directory, which contains
some longer scripts, kindly donated by users of the module.
BUGS
With remote quotas we have to rely on the remote system to
state correctly which block size the quota values are
referring to. Old versions of the Linux rpc.rquotad
reported a block size of 4 kilobytes, which was wildly
incorrect. For more info on this and other Linux bugs please
see INSTALL.
AUTHORS
This module was created 1995 by Tom Zoerner
(email: tomzo AT users.sourceforge.net)
and since then continually improved and ported to
many operating- and file-systems. Numerous people
have contributed to this process; for a complete
list of names please see the CHANGES document.
The quota module was in the public domain 1995-2001. Since 2001
it is licensed under both the Perl Artistic License and version 2
or later of the GNU General Public License as published by the
Free Software Foundation. For a copy of these licenses see
<http://www.opensource.org/licenses/>. The respective authors
of the source code are it's owner in regard to copyright.
SEE ALSO
perl(1), edquota(1m), quotactl(2) or quotactl(7I),
mount(1m), mtab(4) or mnttab(4), quotaon(1m), setmntent(3),
getmntent(3) or getmntinfo(3), endmntent(3), rpc(3),
rquotad(1m).